README.md

<h1 align="center"><b>LeetCode Java Solutions</b></h1>
</br>

<div align="center">
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<p>Hi &#128075, I'm <a href="https://github.com/cheehwatang"><em>Chee Hwa</em></a> and welcome to LeetCode Solutions in Java.</p></br>
<p>As I'm new to <a href="https://leetcode.com/cheehwatang/">LeetCode</a> and programming in general, I'm practicing everyday and hope to share my solutions and learnings with you.</p>
<ul>
  <li>Exclusively on Java</li>
  <li>Beginner problems</li>
  <li>Daily Challenge if within my ability</li>
</ul>
</br>
<hr>

<h2 align='center' id="latest-solutions"><b>Latest Solutions</b></h2>
</br>
<table>
  <tr>
    <th>Date</th>
    <th>Problem</th>
    <th>Difficulty</th>
    <th>Solution</th>
    <th>Topics</th>
  </tr>
  <tr>
    <td align="center">September 14th</td>
    <td>1775. <a href="https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/">Equal Sum Arrays With Minimum Number of Operations</a></td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1775.%20Equal%20Sum%20Arrays%20With%20Minimum%20Number%20of%20Operations/EqualSumArraysWithMinimumNumberOfOperations_Counting.java">Counting</a>
    </td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>
    </td>
  </tr>
  <tr>
    <td align="center">September 13th</td>
    <td>1814. <a href="https://leetcode.com/problems/count-nice-pairs-in-an-array/">Count Nice Pairs in an Array</a></td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1814.%20Count%20Nice%20Pairs%20in%20an%20Array/CountNicePairsInAnArray.java">Counting & Hash Table</a>
    </td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>
    </td>
  </tr>
  <tr>
    <td align="center">September 12th</td>
    <td>2006. <a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_HashTable.java">Hash Table</a>
    </td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
  </tr>
  <tr>
    <td align="center">September 11th</td>
    <td>2006. <a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_Counting.java">Counting</a>
    </td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>
    </td>
  </tr>
  <tr>
    <td align="center">September 10th</td>
    <td>2006. <a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK.java">Brute Force</a>
    </td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
  </tr>
</table>
</br>
<hr>

<details open><summary><h3 id="topics">Topics</h3></summary>
<blockquote>The problem sets and solutions are grouped into Topics as stated in LeetCode.</blockquote>
<ul>
  <li><a href="#array">Array</a></li>
  <li><a href="#backtracking">Backtracking</a></li>
  <li><a href="#binary-search">Binary Search</a></li>
  <li><a href="#binary-search-tree">Binary Search Tree</a></li>
  <li><a href="#binary-tree">Binary Tree</a></li>
  <li><a href="#bit-manipulation">Bit Manipulation</a></li>
  <li><a href="#brainteaser">Brainteaser</a></li>
  <li><a href="#breadth-first-search">Breadth-First Search</a></li>
  <li><a href="#bucket-sort">Bucket Sort</a></li>
  <li><a href="#counting">Counting</a></li>
  <li><a href="#counting-sort">Counting Sort</a></li>
  <li><a href="#data-stream">Data Stream</a></li>
  <li><a href="#depth-first-search">Depth-First Search</a></li>
  <li><a href="#design">Design</a></li>
  <li><a href="#divide-and-conquer">Divide and Conquer</a></li>
  <li><a href="#dynamic-programming">Dynamic Programming</a></li>
  <li><a href="#enumeration">Enumeration</a></li>
  <li><a href="#geometry">Geometry</a></li>
  <li><a href="#graph">Graph</a></li>
  <li><a href="#greedy">Greedy</a></li>
  <li><a href="#hash-table">Hash Table</a></li>
  <li><a href="#heap-priority-queue">Heap (Priority Queue)</a></li>
  <li><a href="#interactive">Interactive</a></li>
  <li><a href="#linked-list">Linked List</a></li>
  <li><a href="#math">Math</a></li>
  <li><a href="#matrix">Matrix</a></li>
  <li><a href="#memoization">Memoization</a></li>
  <li><a href="#monotonic-stack">Monotonic Stack</a></li>
  <li><a href="#number-theory">Number Theory</a></li>
  <li><a href="#ordered-set">Ordered Set</a></li>
  <li><a href="#prefix-sum">Prefix Sum</a></li>
  <li><a href="#queue">Queue</a></li>
  <li><a href="#recursion">Recursion</a></li>
  <li><a href="#simulation">Simulation</a></li>
  <li><a href="#sliding-window">Sliding Window</a></li>
  <li><a href="#sorting">Sorting</a></li>
  <li><a href="#stack">Stack</a></li>
  <li><a href="#string">String</a></li>
  <li><a href="#tree">Tree</a></li>
  <li><a href="#two-pointers">Two Pointers</a></li>
  <li><a href="#union-find">Union Find</a></li>
</ul>
</details>
</br>
<hr>

<details><summary><h3 id="array">Array</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">1</td>
    <td><a href="https://leetcode.com/problems/two-sum/">Two Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1.%20Two%20Sum/TwoSum_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">15</td>
    <td><a href="https://leetcode.com/problems/3sum/">3Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/15.%203Sum/ThreeSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">16</td>
    <td><a href="https://leetcode.com/problems/3sum-closest/">3Sum Closest</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/16.%203Sum%20Closest/ThreeSumClosest.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">26</td>
    <td><a href="https://leetcode.com/problems/remove-duplicates-from-sorted-array/">Remove Duplicates from Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/26.%20Remove%20Duplicates%20from%20Sorted%20Array/RemoveDuplicatesFromSortedArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">27</td>
    <td><a href="https://leetcode.com/problems/remove-element/">Remove Element</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/27.%20Remove%20Element/RemoveElement.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">36</td>
    <td><a href="https://leetcode.com/problems/valid-sudoku/">Valid Sudoku</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">37</td>
    <td><a href="https://leetcode.com/problems/sudoku-solver/">Sudoku Solver</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/37.%20Sudoku%20Solver/SudokuSolver.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">45</td>
    <td><a href="https://leetcode.com/problems/jump-game-ii/">Jump Game II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Memoization.java">Dynamic Programming (Memoization)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Tabulation.java">Dynamic Programming (Tabulation)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">46</td>
    <td><a href="https://leetcode.com/problems/permutations/">Permutations</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Backtracking_Recursion.java">Backtracking</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Iteration.java">Iteration</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Recursion.java">Recursion</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">49</td>
    <td><a href="https://leetcode.com/problems/group-anagrams/">Group Anagrams</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/49.%20Group%20Anagrams/GroupAnagrams.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">55</td>
    <td><a href="https://leetcode.com/problems/jump-game/">Jump Game</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_DynamicProgramming.java">Dynamic Programming</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">57</td>
    <td><a href="https://leetcode.com/problems/insert-interval/">Insert Interval</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/57.%20Insert%20Interval/InsertInterval.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">73</td>
    <td><a href="https://leetcode.com/problems/set-matrix-zeroes/">Set Matrix Zeroes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_Array.java">Array</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_InPlace.java">In-Place</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">79</td>
    <td><a href="https://leetcode.com/problems/word-search/">Word Search</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/79.%20Word%20Search/WordSearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">80</td>
    <td><a href="https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/">Remove Duplicates from Sorted Array II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/80.%20Remove%20Duplicates%20from%20Sorted%20Array%20II/RemoveDuplicatesFromSortedArrayII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">88</td>
    <td><a href="https://leetcode.com/problems/merge-sorted-array/">Merge Sorted Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_Sorting.java">Sorting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">121</td>
    <td><a href="https://leetcode.com/problems/best-time-to-buy-and-sell-stock/">Best Time to Buy and Sell Stock</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/121.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock/BestTimeToBuyAndSellStock_DynamicProgramming.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/121.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock/BestTimeToBuyAndSellStock.java">without</a> Dynamic Programming
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">130</td>
    <td><a href="https://leetcode.com/problems/surrounded-regions/">Surrounded Regions</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_DFS.java">Depth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_UnionFind.java">Union Find</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">134</td>
    <td><a href="https://leetcode.com/problems/gas-station/">Gas Station</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/134.%20Gas%20Station/GasStation.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">136</td>
    <td><a href="https://leetcode.com/problems/single-number/">Single Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/136.%20Single%20Number/SingleNumber.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/136.%20Single%20Number/SingleNumber_StreamReduce.java"><em>Stream Reduce</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">152</td>
    <td><a href="https://leetcode.com/problems/maximum-product-subarray/">Maximum Product Subarray</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/152.%20Maximum%20Product%20Subarray/MaximumProductSubarray.java">Array</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/152.%20Maximum%20Product%20Subarray/MaximumProductSubarray_DynamicProgramming.java">Dynamic Programming</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">167</td>
    <td><a href="https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/">Two Sum II - Input Array is Sorted</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_BinarySearch.java">Binary Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">169</td>
    <td><a href="https://leetcode.com/problems/majority-element/">Majority Element</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_BoyerMooreVotingAlgorithm.java">Boyer-Moore Majority Voting Algorithm</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_DivideAndConquer_Counting.java">Counting & Divide and Conquer</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_HashTable_Counting.java">Counting & Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#divide-and-conquer">Divide and Conquer</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">200</td>
    <td><a href="https://leetcode.com/problems/number-of-islands/">Number of Islands</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_DFS.java">Depth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_UnionFind.java">Union Find</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">217</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate/">Contains Duplicate</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashMap.java">Hash Map</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashSet.java">Hash Set</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">219</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-ii/">Contains Duplicate II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_HashMap.java">Hash Map</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_SlidingWindow.java">Sliding Window</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">220</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-iii/">Contains Duplicate III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_HashMap_BucketSort.java">Sliding Window & Bucket Sort</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_TreeSet_OrderedSet.java">Sliding Window & Ordered Set</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bucket-sort">Bucket Sort</a>,
      <a href="#ordered-set">Ordered Set</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">228</td>
    <td><a href="https://leetcode.com/problems/summary-ranges/">Summary Ranges</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/228.%20Summary%20Ranges/SummaryRanges.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">229</td>
    <td><a href="https://leetcode.com/problems/majority-element-ii/">Majority Element II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_BoyerMooreVotingAlgorithm.java">Boyer-Moore Majority Voting Algorithm</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_HashTable_Counting.java">Counting & Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">238</td>
    <td><a href="https://leetcode.com/problems/product-of-array-except-self/">Product of Array Except Self</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/238.%20Product%20of%20Array%20Except%20Self/ProductOfArrayExceptSelf.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">274</td>
    <td><a href="https://leetcode.com/problems/h-index/">H-Index</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_CountingSort.java">Counting Sort</a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">275</td>
    <td><a href="https://leetcode.com/problems/h-index-ii/">H-Index II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/275.%20H-Index%20II/HIndexII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">283</td>
    <td><a href="https://leetcode.com/problems/move-zeroes/">Move Zeroes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/283.%20Move%20Zeroes/MoveZeroes.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">334</td>
    <td><a href="https://leetcode.com/problems/increasing-triplet-subsequence/">Increasing Triplet Subsequence</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/334.%20Increasing%20Triplet%20Subsequence/IncreasingTripletSubsequence.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">368</td>
    <td><a href="https://leetcode.com/problems/largest-divisible-subset/">Largest Divisible Subset</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/368.%20Largest%20Divisible%20Subset/LargestDivisibleSubset.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">393</td>
    <td><a href="https://leetcode.com/problems/utf-8-validation/">UTF-8 Validation</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/393.%20UTF-8%20Validation/UTF8Validation.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/393.%20UTF-8%20Validation/UTF8Validation_BitManipulation.java">with Bit Manipulation</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">414</td>
    <td><a href="https://leetcode.com/problems/third-maximum-number/">Third Maximum Number</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber.java">with Sorting</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber_Sorting.java">without Sorting</a> or with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber_PriorityQueue_HashSet.java"><em>Hash Table & Priority Queue</em></a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">448</td>
    <td><a href="https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/">Find All Numbers Disappeared in an Array</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/448.%20Find%20All%20Numbers%20Disappeared%20in%20an%20Array/FindAllNumbersDisappearedInAnArray_HashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/448.%20Find%20All%20Numbers%20Disappeared%20in%20an%20Array/FindAllNumbersDisappearedInAnArray.java">without</a> Hash Table
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">485</td>
    <td><a href="https://leetcode.com/problems/max-consecutive-ones/">Maximum Consecutive Ones</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/485.%20Maximum%20Consecutive%20Ones/MaxConsecutiveOnes.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">496</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-i/">Next Greater Element I</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/496.%20Next%20Greater%20Element%20I/NextGreaterElementI_HashTable_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">503</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-ii/">Next Greater Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/503.%20Next%20Greater%20Element%20II/NextGreaterElementII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">523</td>
    <td><a href="https://leetcode.com/problems/continuous-subarray-sum/">Continuous Subarray Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/523.%20Continuous%20Subarray%20Sum/ContinuousSubarraySum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">560</td>
    <td><a href="https://leetcode.com/problems/subarray-sum-equals-k/">Subarray Sum Equals K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/560.%20Subarray%20Sum%20Equals%20K/SubarraySumEqualsK.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">561</td>
    <td><a href="https://leetcode.com/problems/array-partition/">Array Partition</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_CountingSort_Greedy.java">Greedy & Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_Sorting_Greedy.java">Greedy & Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">609</td>
    <td><a href="https://leetcode.com/problems/find-duplicate-file-in-system/">Find Duplicate File in System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/609.%20Find%20Duplicate%20File%20in%20System/FindDuplicateFileInSystem_HashMap.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">645</td>
    <td><a href="https://leetcode.com/problems/set-mismatch/">Set Mismatch</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_BitManipulation.java">Bit Manipulation</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">713</td>
    <td><a href="https://leetcode.com/problems/subarray-product-less-than-k/">Subarray Product Less Than K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/713.%20Subarray%20Product%20Less%20Than%20K/SubarrayProductLessThanK.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">744</td>
    <td><a href="https://leetcode.com/problems/find-smallest-letter-greater-than-target/">Find Smallest Letter Greater Than Target</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/744.%20Find%20Smallest%20Letter%20Greater%20Than%20Target/FindSmallestLetterGreaterThanTarget.java">Linear Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/744.%20Find%20Smallest%20Letter%20Greater%20Than%20Target/FindSmallestLetterGreaterThanTarget_BinarySearch.java">Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">746</td>
    <td><a href="https://leetcode.com/problems/min-cost-climbing-stairs/">Min Cost Climbing Stairs</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/746.%20Min%20Cost%20Climbing%20Stairs/MinCostClimbingStairs_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/746.%20Min%20Cost%20Climbing%20Stairs/MinCostClimbingStairs_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">766</td>
    <td><a href="https://leetcode.com/problems/toeplitz-matrix/">Toeplitz Matrix</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td>Follow up:
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix_OneRowAtATime.java">One Row at a Time</a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix_OneColumnAtATime.java">One Column at a Time</a>
    </td>
  </tr>
  <tr>
    <td align="center">812</td>
    <td><a href="https://leetcode.com/problems/largest-triangle-area/">Largest Triangle Area</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/812.%20Largest%20Triangle%20Area/LargestTriangleArea.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">835</td>
    <td><a href="https://leetcode.com/problems/image-overlap/">Image Overlap</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/835.%20Image%20Overlap/ImageOverlap_BitManipulation.java">Bit Manipulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/835.%20Image%20Overlap/ImageOverlap_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">904</td>
    <td><a href="https://leetcode.com/problems/fruit-into-baskets/">Fruit Into Baskets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/904.%20Fruit%20Into%20Baskets/FruitIntoBaskets.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a><a>, </a>
      <a href="#hash-table">Hash Table</a><a>, </a>
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">905</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity/">Sort Array By Parity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/905.%20Sort%20Array%20By%20Parity/SortArrayByParity.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">922</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity-ii/">Sort Array By Parity II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/922.%20Sort%20Array%20By%20Parity%20II/SortArrayByParityII.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">923</td>
    <td><a href="https://leetcode.com/problems/3sum-with-multiplicity/">3Sum With Multiplicity</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Counting.java">Counting</a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Sorting_TwoPointers.java">Sorting & Two Pointers</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">929</td>
    <td><a href="https://leetcode.com/problems/unique-email-addresses/">Unique Email Addresses</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/929.%20Unique%20Email%20Addresses/UniqueEmailAddresses_HashSet.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">941</td>
    <td><a href="https://leetcode.com/problems/valid-mountain-array/">Valid Mountain Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/941.%20Valid%20Mountain%20Array/ValidMountainArray_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">944</td>
    <td><a href="https://leetcode.com/problems/delete-columns-to-make-sorted/">Delete Columns to Make Sorted</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/944.%20Delete%20Columns%20to%20Make%20Sorted/DeleteColumnsToMakeSorted.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">948</td>
    <td><a href="https://leetcode.com/problems/bag-of-tokens/">Bag of Tokens</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/948.%20Bag%20of%20Tokens/BagOfTokens.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">953</td>
    <td><a href="https://leetcode.com/problems/verifying-an-alien-dictionary/">Verifying an Alien Dictionary</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/953.%20Verifying%20an%20Alien%20Dictionary/VerifyingAnAlienDictionary.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">974</td>
    <td><a href="https://leetcode.com/problems/subarray-sums-divisible-by-k/">Subarray Sums Divisible by K</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">976</td>
    <td><a href="https://leetcode.com/problems/largest-perimeter-triangle/">Largest Perimeter Triangle</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/976.%20Largest%20Perimeter%20Triangle/LargestPerimeterTriangle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">977</td>
    <td><a href="https://leetcode.com/problems/squares-of-a-sorted-array/">Squares of a Sorted Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_Sorting.java">Sorting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">985</td>
    <td><a href="https://leetcode.com/problems/sum-of-even-numbers-after-queries/">Sum of Even Numbers After Queries</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/985.%20Sum%20of%20Even%20Numbers%20After%20Queries/SumOfEvenNumbersAfterQueries.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">989</td>
    <td><a href="https://leetcode.com/problems/add-to-array-form-of-integer/">Add to Array-Form of Integer</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/989.%20Add%20to%20Array-Form%20of%20Integer/AddToArrayFormOfInteger.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1019</td>
    <td><a href="https://leetcode.com/problems/next-greater-node-in-linked-list/">Next Greater Node In Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1019.%20Next%20Greater%20Node%20In%20Linked%20List/NextGreaterNodeInLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1037</td>
    <td><a href="https://leetcode.com/problems/valid-boomerang/">Valid Boomerang</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1037.%20Valid%20Boomerang/ValidBoomerang.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1051</td>
    <td><a href="https://leetcode.com/problems/height-checker/">Height Checker</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_CountingSort.java">Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1089</td>
    <td><a href="https://leetcode.com/problems/duplicate-zeros/">Duplicate Zeros</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1089.%20Duplicate%20Zeros/DuplicateZeros.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1089.%20Duplicate%20Zeros/DuplicateZeros_TwoPointers.java">with Two Pointers</a></td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1122</td>
    <td><a href="https://leetcode.com/problems/relative-sort-array/">Relative Sort Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_CountingSort_Sorting.java">Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1207</td>
    <td><a href="https://leetcode.com/problems/unique-number-of-occurrences/">Unique Number of Occurrences</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1207.%20Unique%20Number%20of%20Occurrences/UniqueNumberOfOccurrences_Counting_Sorting.java">Counting & Sorting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1207.%20Unique%20Number%20of%20Occurrences/UniqueNumberOfOccurrences_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1232</td>
    <td><a href="https://leetcode.com/problems/check-if-it-is-a-straight-line/">Check If It Is a Straight Line</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1232.%20Check%20If%20It%20Is%20a%20Straight%20Line/CheckIfItIsAStraightLine.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1239</td>
    <td><a href="https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters/">Maximum Length of a Concatenated String with Unique Characters</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_Backtracking.java">Backtracking</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_BitManipulation.java">Bit Manipulation</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1295</td>
    <td><a href="https://leetcode.com/problems/find-numbers-with-even-number-of-digits/">Find Numbers with Even Number of Digits</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1295.%20Find%20Numbers%20with%20Even%20Number%20of%20Digits/FindNumbersWithEvenNumberOfDigits.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1299</td>
    <td><a href="https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/">Replace Elements with Greatest Element on Right Side</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1299.%20Replace%20Elements%20with%20Greatest%20Element%20on%20Right%20Side/ReplaceElementsWithGreatestElementOnRightSide.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1337</td>
    <td><a href="https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/">The K Weakest Rows in a Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix.java">Linear Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch.java">Binary Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_PriorityQueue.java">Heap (Priority Queue) & Binary Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_Sorting.java">Sorting & Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1346</td>
    <td><a href="https://leetcode.com/problems/check-if-n-and-its-double-exist/">Check If N and Its Double Exist</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_Sorting_BinarySearch.java">Binary Search & Sorting</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1351</td>
    <td><a href="https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix/">Count Negative Numbers in a Sorted Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix.java">Linear Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix_BinarySearch.java">Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1470</td>
    <td><a href="https://leetcode.com/problems/shuffle-the-array/">Shuffle the Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1470.%20Shuffle%20the%20Array/ShuffleTheArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1480</td>
    <td><a href="https://leetcode.com/problems/running-sum-of-1d-array/">Running Sum of 1D Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1480.%20Running%20Sum%20of%201D%20Array/RunningSumOf1DArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1497</td>
    <td><a href="https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k/">Check If Array Pairs Are Divisible by k</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1534</td>
    <td><a href="https://leetcode.com/problems/count-good-triplets/">Count Good Triplets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1534.%20Count%20Good%20Triplets/CountGoodTriplets.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#enumeration">Enumeration</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1578</td>
    <td><a href="https://leetcode.com/problems/minimum-time-to-make-rope-colorful/">Minimum Time to Make Rope Colorful</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_DynamicProgramming.java">Dynamic Programming</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1636</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-increasing-frequency/">Sort Array by Increasing Frequency</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1636.%20Sort%20Array%20by%20Increasing%20Frequency/SortArrayByIncreasingFrequency.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1662</td>
    <td><a href="https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/">Check If Two String Arrays are Equivalent</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1662.%20Check%20If%20Two%20String%20Arrays%20are%20Equivalent/CheckIfTwoStringArraysAreEquivalent_Pointers.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1662.%20Check%20If%20Two%20String%20Arrays%20are%20Equivalent/CheckIfTwoStringArraysAreEquivalent_String.java">without Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1672</td>
    <td><a href="https://leetcode.com/problems/richest-customer-wealth/">Richest Customer Wealth</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1672.%20Richest%20Customer%20Wealth/RichestCustomerWealth.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1679</td>
    <td><a href="https://leetcode.com/problems/max-number-of-k-sum-pairs/">Max Number of K-Sum Pairs</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_Sorting_TwoPointers.java">Sorting & Two Pointers</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1711</td>
    <td><a href="https://leetcode.com/problems/count-good-meals/">Count Good Meals</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1711.%20Count%20Good%20Meals/CountGoodMeals.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1732</td>
    <td><a href="https://leetcode.com/problems/find-the-highest-altitude/">Find the Highest Altitude</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1732.%20Find%20the%20Highest%20Altitude/FindTheHighestAltitude.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1775</td>
    <td><a href="https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/">Equal Sum Arrays With Minimum Number of Operations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1775.%20Equal%20Sum%20Arrays%20With%20Minimum%20Number%20of%20Operations/EqualSumArraysWithMinimumNumberOfOperations_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1814</td>
    <td><a href="https://leetcode.com/problems/count-nice-pairs-in-an-array/">Count Nice Pairs in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1814.%20Count%20Nice%20Pairs%20in%20an%20Array/CountNicePairsInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1833</td>
    <td><a href="https://leetcode.com/problems/maximum-ice-cream-bars/">Maximum Ice Cream Bars</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1833.%20Maximum%20Ice%20Cream%20Bars/MaximumIceCreamBars.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1834</td>
    <td><a href="https://leetcode.com/problems/single-threaded-cpu/">Single-Threaded CPU</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1834.%20Single-Threaded%20CPU/SingleThreadedCPU.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1865</td>
    <td><a href="https://leetcode.com/problems/finding-pairs-with-a-certain-sum/">Finding Pairs With a Certain Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1865.%20Finding%20Pairs%20With%20a%20Certain%20Sum/FindingPairsWithACertainSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#design">Design</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1920</td>
    <td><a href="https://leetcode.com/problems/build-array-from-permutation/">Build Array from Permutation</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1920.%20Build%20Array%20from%20Permutation/BuildArrayFromPermutation.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1926</td>
    <td><a href="https://leetcode.com/problems/nearest-exit-from-entrance-in-maze/">Nearest Exit from Entrance in Maze</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1926.%20Nearest%20Exit%20from%20Entrance%20in%20Maze/NearestExitFromEntranceInMaze.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1962</td>
    <td><a href="https://leetcode.com/problems/remove-stones-to-minimize-the-total/">Remove Stones to Minimize the Total</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1962.%20Remove%20Stones%20to%20Minimize%20the%20Total/RemoveStonesToMinimizeTheTotal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1979</td>
    <td><a href="https://leetcode.com/problems/find-greatest-common-divisor-of-array/">Find Greatest Common Divisor of Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1979.%20Find%20Greatest%20Common%20Divisor%20of%20Array/FindGreatestCommonDivisorOfArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#number-theory">Number Theory</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1995</td>
    <td><a href="https://leetcode.com/problems/count-special-quadruplets/">Count Special Quadruplets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1995.%20Count%20Special%20Quadruplets/CountSpecialQuadruplets.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#enumeration">Enumeration</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1995.%20Count%20Special%20Quadruplets/CountSpecialQuadruplets_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2006</td>
    <td><a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK.java">Brute Force</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2007</td>
    <td><a href="https://leetcode.com/problems/find-original-array-from-doubled-array/">Find Original Array From Doubled Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_HashMap_Sorting.java">Hash Table</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Queue_Sorting.java">Queue</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Counting.java">Counting Array</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2023</td>
    <td><a href="https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target/">Number of Pairs of Strings With Concatenation Equal to Target</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2023.%20Number%20of%20Pairs%20of%20Strings%20With%20Concatenation%20Equal%20to%20Target/NumberOfPairsOfStringsWithConcatenationEqualToTarget_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2028</td>
    <td><a href="https://leetcode.com/problems/find-missing-observations/">Find Missing Observations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2028.%20Find%20Missing%20Observations/FindMissingObservations.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2131</td>
    <td><a href="https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/">Longest Palindrome by Concatenating Two Letter Words</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2133</td>
    <td><a href="https://leetcode.com/problems/check-if-every-row-and-column-contains-all-numbers/">Check if Every Row and Column Contains All Numbers</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2136</td>
    <td><a href="https://leetcode.com/problems/earliest-possible-day-of-full-bloom/">Earliest Possible Day of Full Bloom</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2136.%20Earliest%20Possible%20Day%20of%20Full%20Bloom/EarliestPossibleDayOfFullBloom.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2176</td>
    <td><a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Equal and Divisible Pairs in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2176.%20Count%20Equal%20and%20Divisible%20Pairs%20in%20an%20Array/CountEqualAndDivisiblePairsInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2244</td>
    <td><a href="https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks/">Minimum Rounds to Complete All Tasks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2244.%20Minimum%20Rounds%20to%20Complete%20All%20Tasks/MinimumRoundsToCompleteAllTasks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2279</td>
    <td><a href="https://leetcode.com/problems/maximum-bags-with-full-capacity-of-rocks/">Maximum Bags With Full Capacity of Rocks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2279.%20Maximum%20Bags%20With%20Full%20Capacity%20of%20Rocks/MaximumBagsWithFullCapacityOfRocks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2352</td>
    <td><a href="https://leetcode.com/problems/equal-row-and-column-pairs/">Equal Row and Column Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2352.%20Equal%20Row%20and%20Column%20Pairs/EqualRowAndColumnPairs.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2389</td>
    <td><a href="https://leetcode.com/problems/longest-subsequence-with-limited-sum/">Longest Subsequence With Limited Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2389.%20Longest%20Subsequence%20With%20Limited%20Sum/LongestSubsequenceWithLimitedSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#prefix-sum">Prefix Sum</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2395</td>
    <td><a href="https://leetcode.com/problems/find-subarrays-with-equal-sum/">Find Subarrays With Equal Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2395.%20Find%20Subarrays%20With%20Equal%20Sum/FindSubarraysWithEqualSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2399</td>
    <td><a href="https://leetcode.com/problems/check-distances-between-same-letters/">Check Distances Between Same Letters</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2438</td>
    <td><a href="https://leetcode.com/problems/range-product-queries-of-powers/">Range Product Queries of Powers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2438.%20Range%20Product%20Queries%20of%20Powers/RangeProductQueriesOfPowers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2452</td>
    <td><a href="https://leetcode.com/problems/words-within-two-edits-of-dictionary/">Words Within Two Edits of Dictionary</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2452.%20Words%20Within%20Two%20Edits%20of%20Dictionary/WordsWithinTwoEditsOfDictionary.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2453</td>
    <td><a href="https://leetcode.com/problems/destroy-sequential-targets/">Destroy Sequential Targets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2453.%20Destroy%20Sequential%20Targets/DestroySequentialTargets_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2454</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iv/">Next Greater Element IV</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2454.%20Next%20Greater%20Element%20IV/NextGreaterElementIV_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="backtracking">Backtracking</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">37</td>
    <td><a href="https://leetcode.com/problems/sudoku-solver/">Sudoku Solver</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/37.%20Sudoku%20Solver/SudokuSolver.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">46</td>
    <td><a href="https://leetcode.com/problems/permutations/">Permutations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Backtracking_Recursion.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Iteration.java"><em>Iteration</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/46.%20Permutations/Permutations_Recursion.java"><em>Recursion</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">79</td>
    <td><a href="https://leetcode.com/problems/word-search/">Word Search</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/79.%20Word%20Search/WordSearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">113</td>
    <td><a href="https://leetcode.com/problems/path-sum-ii/">Path Sum II</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">257</td>
    <td><a href="https://leetcode.com/problems/binary-tree-paths/">Binary Tree Paths</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">797</td>
    <td><a href="https://leetcode.com/problems/all-paths-from-source-to-target/">All Paths From Source to Target</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive_Backtracking.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_BFS.java"><em>Breadth-First Search</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">967</td>
    <td><a href="https://leetcode.com/problems/numbers-with-same-consecutive-differences/">Numbers With Same Consecutive Differences</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/967.%20Numbers%20With%20Same%20Consecutive%20Differences/NumbersWithSameConsecutiveDifferences_Backtracking.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/967.%20Numbers%20With%20Same%20Consecutive%20Differences/NumbersWithSameConsecutiveDifferences_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1239</td>
    <td><a href="https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters/">Maximum Length of a Concatenated String with Unique Characters</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_Backtracking.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_BitManipulation.java"><em>Bit Manipulation</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="binary-search">Binary Search</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">102</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal/">Binary Tree Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/102.%20Binary%20Tree%20Level%20Order%20Traversal/BinaryTreeLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">103</td>
    <td><a href="https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/">Binary Tree Zigzag Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/103.%20Binary%20Tree%20Zigzag%20Level%20Order%20Traversal/BinaryTreeZigzagLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">107</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal-ii/">Binary Tree Level Order Traversal II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/107.%20Binary%20Tree%20Level%20Order%20Traversal%20II/BinaryTreeLevelOrderTraversalII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">144</td>
    <td><a href="https://leetcode.com/problems/binary-tree-preorder-traversal/">Binary Tree Preorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">145</td>
    <td><a href="https://leetcode.com/problems/binary-tree-postorder-traversal/">Binary Tree Postorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">167</td>
    <td><a href="https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/">Two Sum II - Input Array is Sorted</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_BinarySearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">222</td>
    <td><a href="https://leetcode.com/problems/count-complete-tree-nodes/">Count Complete Tree Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/222.%20Count%20Complete%20Tree%20Nodes/CountCompleteTreeNodes.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">275</td>
    <td><a href="https://leetcode.com/problems/h-index-ii/">H-Index II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/275.%20H-Index%20II/HIndexII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">374</td>
    <td><a href="https://leetcode.com/problems/guess-number-higher-or-lower/">Guess Number Higher or Lower</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/374.%20Guess%20Number%20Higher%20or%20Lower/GuessNumberHigherOrLower_BinarySearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#interactive">Interactive</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">744</td>
    <td><a href="https://leetcode.com/problems/find-smallest-letter-greater-than-target/">Find Smallest Letter Greater Than Target</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/744.%20Find%20Smallest%20Letter%20Greater%20Than%20Target/FindSmallestLetterGreaterThanTarget_BinarySearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/744.%20Find%20Smallest%20Letter%20Greater%20Than%20Target/FindSmallestLetterGreaterThanTarget.java"><em>Linear Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1337</td>
    <td><a href="https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/">The K Weakest Rows in a Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch.java">Binary Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_PriorityQueue.java">Heap (Priority Queue) & Binary Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_Sorting.java">Sorting & Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix.java"><em>Linear Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1346</td>
    <td><a href="https://leetcode.com/problems/check-if-n-and-its-double-exist/">Check If N and Its Double Exist</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_Sorting_BinarySearch.java">Binary Search & Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_HashTable.java"><em>Hash Table</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1351</td>
    <td><a href="https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix/">Count Negative Numbers in a Sorted Matrix</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix_BinarySearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix.java"><em>Linear Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2389</td>
    <td><a href="https://leetcode.com/problems/longest-subsequence-with-limited-sum/">Longest Subsequence With Limited Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2389.%20Longest%20Subsequence%20With%20Limited%20Sum/LongestSubsequenceWithLimitedSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#prefix-sum">Prefix Sum</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="binary-search-tree">Binary Search Tree</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">98</td>
    <td><a href="https://leetcode.com/problems/validate-binary-search-tree/">Validate Binary Search Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java">Breadth-First Search (with Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java">Breadth-First Search (without Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java">Depth-First Search (Iterative)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java">Depth-First Search (Recursive)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java">Two Pointers (with Iterative Inorder Traversal)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java">Two Pointers (with Recursive Inorder Traversal)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">783</td>
    <td><a href="https://leetcode.com/problems/minimum-distance-between-bst-nodes/">Minimum Distance Between BST Nodes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="binary-tree">Binary Tree</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">94</td>
    <td><a href="https://leetcode.com/problems/binary-tree-inorder-traversal/">Binary Tree Inorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">98</td>
    <td><a href="https://leetcode.com/problems/validate-binary-search-tree/">Validate Binary Search Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">100</td>
    <td><a href="https://leetcode.com/problems/same-tree/">Same Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_BFS.java">Breadth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_DFS.java">Depth-First Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">104</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">110</td>
    <td><a href="https://leetcode.com/problems/balanced-binary-tree/">Balanced Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/110.%20Balanced%20Binary%20Tree/BalancedBinaryTree.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">111</td>
    <td><a href="https://leetcode.com/problems/minimum-depth-of-binary-tree/">Minimum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">112</td>
    <td><a href="https://leetcode.com/problems/path-sum/">Path Sum</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">113</td>
    <td><a href="https://leetcode.com/problems/path-sum-ii/">Path Sum II</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">114</td>
    <td><a href="https://leetcode.com/problems/flatten-binary-tree-to-linked-list/">Flatten Binary Tree to Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">129</td>
    <td><a href="https://leetcode.com/problems/sum-root-to-leaf-numbers/">Sum Root to Leaf Numbers</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">222</td>
    <td><a href="https://leetcode.com/problems/count-complete-tree-nodes/">Count Complete Tree Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/222.%20Count%20Complete%20Tree%20Nodes/CountCompleteTreeNodes.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">226</td>
    <td><a href="https://leetcode.com/problems/invert-binary-tree/">Invert Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">257</td>
    <td><a href="https://leetcode.com/problems/binary-tree-paths/">Binary Tree Paths</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">404</td>
    <td><a href="https://leetcode.com/problems/sum-of-left-leaves/">Sum of Left Leaves</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">437</td>
    <td><a href="https://leetcode.com/problems/path-sum-iii/">Path Sum III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java">Breadth-First Search (with Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java">Breadth-First Search (without Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java">Depth-First Search (Iterative)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java">Depth-First Search (Recursive)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java">Two Pointers (with Iterative Inorder Traversal)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java">Two Pointers (with Recursive Inorder Traversal)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">783</td>
    <td><a href="https://leetcode.com/problems/minimum-distance-between-bst-nodes/">Minimum Distance Between BST Nodes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">988</td>
    <td><a href="https://leetcode.com/problems/smallest-string-starting-from-leaf/">Smallest String Starting From Leaf</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1026</td>
    <td><a href="https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/">Maximum Difference Between Node and Ancestor</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1457</td>
    <td><a href="https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/">Pseudo-Palindromic Paths in a Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="bit-manipulation">Bit Manipulation</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">29</td>
    <td><a href="https://leetcode.com/problems/divide-two-integers/">Divide Two Integers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/29.%20Divide%20Two%20Integers/DivideTwoIntegers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">136</td>
    <td><a href="https://leetcode.com/problems/single-number/">Single Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/136.%20Single%20Number/SingleNumber.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td>Bonus Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/136.%20Single%20Number/SingleNumber_StreamReduce.java"><em>Stream Reduce</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">371</td>
    <td><a href="https://leetcode.com/problems/sum-of-two-integers/">Sum of Two Integers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/371.%20Sum%20of%20Two%20Integers/SumOfTwoIntegers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">393</td>
    <td><a href="https://leetcode.com/problems/utf-8-validation/">UTF-8 Validation</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/393.%20UTF-8%20Validation/UTF8Validation_BitManipulation.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/393.%20UTF-8%20Validation/UTF8Validation.java"><em>without using Bit Manipulation</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">645</td>
    <td><a href="https://leetcode.com/problems/set-mismatch/">Set Mismatch</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_BitManipulation.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_HashTable.java"><em>Hash Table</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1239</td>
    <td><a href="https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters/">Maximum Length of a Concatenated String with Unique Characters</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_BitManipulation.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_Backtracking.java"><em>Backtracking</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1318</td>
    <td><a href="https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c/">Minimum Flips to Make a OR b Equal to c</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1318.%20Minimum%20Flips%20to%20Make%20a%20OR%20b%20Equal%20to%20c/MinimumFlipsToMakeAORBEqualToC.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1342</td>
    <td><a href="https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/">Number of Steps to Reduce a Number to Zero</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1342.%20Numbers%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero/NumberOfStepsToReduceANumberToZero_BitManipulation.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1342.%20Numbers%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero/NumberOfStepsToReduceANumberToZero_Math.java"><em>Math</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1457</td>
    <td><a href="https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/">Pseudo-Palindromic Paths in a Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1486</td>
    <td><a href="https://leetcode.com/problems/xor-operation-in-an-array/">XOR Operation in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1486.%20XOR%20Operation%20in%20an%20Array/XOROperationInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1680</td>
    <td><a href="https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers/">Concatenation of Consecutive Binary Numbers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_BitManipulation.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_Math.java"><em>Math</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2220</td>
    <td><a href="https://leetcode.com/problems/minimum-bit-flips-to-convert-number/">Minimum Bit Flips to Convert Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2220.%20Minimum%20Bit%20Flips%20to%20Convert%20Number/MinimumBitFlipsToConvertNumber.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2438</td>
    <td><a href="https://leetcode.com/problems/range-product-queries-of-powers/">Range Product Queries of Powers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2438.%20Range%20Product%20Queries%20of%20Powers/RangeProductQueriesOfPowers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="brainteaser">Brainteaser</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">1033</td>
    <td><a href="https://leetcode.com/problems/moving-stones-until-consecutive/">Moving Stones Until Consecutive</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1033.%20Moving%20Stones%20Until%20Consecutive/MovingStonesUntilConsecutive.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#brainteaser">Brainteaser</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="breadth-first-search">Breadth-First Search</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">100</td>
    <td><a href="https://leetcode.com/problems/same-tree/">Same Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_DFS.java"><em>Depth-First Search</em>
    </td>
  </tr>
  <tr>
    <td align="center">102</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal/">Binary Tree Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/102.%20Binary%20Tree%20Level%20Order%20Traversal/BinaryTreeLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">103</td>
    <td><a href="https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/">Binary Tree Zigzag Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/103.%20Binary%20Tree%20Zigzag%20Level%20Order%20Traversal/BinaryTreeZigzagLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">104</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">107</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal-ii/">Binary Tree Level Order Traversal II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/107.%20Binary%20Tree%20Level%20Order%20Traversal%20II/BinaryTreeLevelOrderTraversalII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">111</td>
    <td><a href="https://leetcode.com/problems/minimum-depth-of-binary-tree/">Minimum Depth of Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">112</td>
    <td><a href="https://leetcode.com/problems/path-sum/">Path Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">130</td>
    <td><a href="https://leetcode.com/problems/surrounded-regions/">Surrounded Regions</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_DFS.java"><em>Depth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">200</td>
    <td><a href="https://leetcode.com/problems/number-of-islands/">Number of Islands</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_DFS.java"><em>Depth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">226</td>
    <td><a href="https://leetcode.com/problems/invert-binary-tree/">Invert Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">404</td>
    <td><a href="https://leetcode.com/problems/sum-of-left-leaves/">Sum of Left Leaves</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">429</td>
    <td><a href="https://leetcode.com/problems/n-ary-tree-level-order-traversal/">N-ary Tree Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/429.%20N-ary%20Tree%20Level%20Order%20Traversal/NAryTreeLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">559</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java">without Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java"><em>Two Pointers (with Iterative Inorder Traversal)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java"><em>Two Pointers (with Recursive Inorder Traversal)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">783</td>
    <td><a href="https://leetcode.com/problems/minimum-distance-between-bst-nodes/">Minimum Distance Between BST Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">797</td>
    <td><a href="https://leetcode.com/problems/all-paths-from-source-to-target/">All Paths From Source to Target</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive_Backtracking.java"><em>Depth-First Search (Backtracking)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">967</td>
    <td><a href="https://leetcode.com/problems/numbers-with-same-consecutive-differences/">Numbers With Same Consecutive Differences</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/967.%20Numbers%20With%20Same%20Consecutive%20Differences/NumbersWithSameConsecutiveDifferences_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/967.%20Numbers%20With%20Same%20Consecutive%20Differences/NumbersWithSameConsecutiveDifferences_Backtracking.java"><em>Backtracking</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1457</td>
    <td><a href="https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/">Pseudo-Palindromic Paths in a Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1926</td>
    <td><a href="https://leetcode.com/problems/nearest-exit-from-entrance-in-maze/">Nearest Exit from Entrance in Maze</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1926.%20Nearest%20Exit%20from%20Entrance%20in%20Maze/NearestExitFromEntranceInMaze.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1971</td>
    <td><a href="https://leetcode.com/problems/find-if-path-exists-in-graph/">Find if Path Exists in Graph</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_BFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="bucket-sort">Bucket Sort</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
  <td align="center">220</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-iii/">Contains Duplicate III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_HashMap_BucketSort.java">Sliding Window & Bucket Sort</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bucket-sort">Bucket Sort</a>,
      <a href="#ordered-set">Ordered Set</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_TreeSet_OrderedSet.java"><em>Sliding Window & Ordered Set</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="counting">Counting</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">169</td>
    <td><a href="https://leetcode.com/problems/majority-element/">Majority Element</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_DivideAndConquer_Counting.java">Counting & Divide and Conquer</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_HashTable_Counting.java">Counting & Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#divide-and-conquer">Divide and Conquer</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">229</td>
    <td><a href="https://leetcode.com/problems/majority-element-ii/">Majority Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_HashTable_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">383</td>
    <td><a href="https://leetcode.com/problems/ransom-note/">Ransom Note</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">923</td>
    <td><a href="https://leetcode.com/problems/3sum-with-multiplicity/">3Sum With Multiplicity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_HashTable.java"><em>Hash Table</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Sorting_TwoPointers.java"><em>Sorting & Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1497</td>
    <td><a href="https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k/">Check If Array Pairs Are Divisible by k</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1603</td>
    <td><a href="https://leetcode.com/problems/design-parking-system/">Design Parking System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1603.%20Design%20Parking%20System/ParkingSystem.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#design">Design</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1704</td>
    <td><a href="https://leetcode.com/problems/determine-if-string-halves-are-alike/">Determine if String Halves Are Alike</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1704.%20Determine%20if%20String%20Halves%20Are%20Alike/DetermineIfStringHalvesAreAlike.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1775</td>
    <td><a href="https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/">Equal Sum Arrays With Minimum Number of Operations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1775.%20Equal%20Sum%20Arrays%20With%20Minimum%20Number%20of%20Operations/EqualSumArraysWithMinimumNumberOfOperations_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1814</td>
    <td><a href="https://leetcode.com/problems/count-nice-pairs-in-an-array/">Count Nice Pairs in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1814.%20Count%20Nice%20Pairs%20in%20an%20Array/CountNicePairsInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2006</td>
    <td><a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK.java"><em>Brute Force Approach</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2131</td>
    <td><a href="https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/">Longest Palindrome by Concatenating Two Letter Words</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2244</td>
    <td><a href="https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks/">Minimum Rounds to Complete All Tasks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2244.%20Minimum%20Rounds%20to%20Complete%20All%20Tasks/MinimumRoundsToCompleteAllTasks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2351</td>
    <td><a href="https://leetcode.com/problems/first-letter-to-appear-twice/">First Letter to Appear Twice</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2453</td>
    <td><a href="https://leetcode.com/problems/destroy-sequential-targets/">Destroy Sequential Targets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2453.%20Destroy%20Sequential%20Targets/DestroySequentialTargets_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="counting-sort">Counting Sort</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">274</td>
    <td><a href="https://leetcode.com/problems/h-index/">H-Index</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_CountingSort.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">561</td>
    <td><a href="https://leetcode.com/problems/array-partition/">Array Partition</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_CountingSort_Greedy.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_Sorting_Greedy.java"><em>Greedy & Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1051</td>
    <td><a href="https://leetcode.com/problems/height-checker/">Height Checker</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_CountingSort.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1122</td>
    <td><a href="https://leetcode.com/problems/relative-sort-array/">Relative Sort Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_CountingSort_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="data-stream">Data Stream</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">295</td>
    <td><a href="https://leetcode.com/problems/find-median-from-data-stream/">Find Median from Data Stream</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/295.%20Find%20Median%20from%20Data%20Stream/MedianFinder_PriorityQueue.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#data-stream">Data Stream</a>,
      <a href="#design">Design</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="depth-first-search">Depth-First Search</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">94</td>
    <td><a href="https://leetcode.com/problems/binary-tree-inorder-traversal/">Binary Tree Inorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">98</td>
    <td><a href="https://leetcode.com/problems/validate-binary-search-tree/">Validate Binary Search Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">100</td>
    <td><a href="https://leetcode.com/problems/same-tree/">Same Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_DFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">104</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">110</td>
    <td><a href="https://leetcode.com/problems/balanced-binary-tree/">Balanced Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/110.%20Balanced%20Binary%20Tree/BalancedBinaryTree.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">111</td>
    <td><a href="https://leetcode.com/problems/minimum-depth-of-binary-tree/">Minimum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">112</td>
    <td><a href="https://leetcode.com/problems/path-sum/">Path Sum</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">113</td>
    <td><a href="https://leetcode.com/problems/path-sum-ii/">Path Sum II</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">114</td>
    <td><a href="https://leetcode.com/problems/flatten-binary-tree-to-linked-list/">Flatten Binary Tree to Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">129</td>
    <td><a href="https://leetcode.com/problems/sum-root-to-leaf-numbers/">Sum Root to Leaf Numbers</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">130</td>
    <td><a href="https://leetcode.com/problems/surrounded-regions/">Surrounded Regions</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_DFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_BFS.java"><em>Breadth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">144</td>
    <td><a href="https://leetcode.com/problems/binary-tree-preorder-traversal/">Binary Tree Preorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">145</td>
    <td><a href="https://leetcode.com/problems/binary-tree-postorder-traversal/">Binary Tree Postorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">200</td>
    <td><a href="https://leetcode.com/problems/number-of-islands/">Number of Islands</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_DFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_BFS.java"><em>Breadth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">222</td>
    <td><a href="https://leetcode.com/problems/count-complete-tree-nodes/">Count Complete Tree Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/222.%20Count%20Complete%20Tree%20Nodes/CountCompleteTreeNodes.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">226</td>
    <td><a href="https://leetcode.com/problems/invert-binary-tree/">Invert Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">257</td>
    <td><a href="https://leetcode.com/problems/binary-tree-paths/">Binary Tree Paths</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">404</td>
    <td><a href="https://leetcode.com/problems/sum-of-left-leaves/">Sum of Left Leaves</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">437</td>
    <td><a href="https://leetcode.com/problems/path-sum-iii/">Path Sum III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">559</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java"><em>Breadth-First Search (with Hash Table)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java"><em>Breadth-First Search (without Hash Table)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java"><em>Two Pointers (with Iterative Inorder Traversal)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java"><em>Two Pointers (with Recursive Inorder Traversal)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">783</td>
    <td><a href="https://leetcode.com/problems/minimum-distance-between-bst-nodes/">Minimum Distance Between BST Nodes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">797</td>
    <td><a href="https://leetcode.com/problems/all-paths-from-source-to-target/">All Paths From Source to Target</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive_Backtracking.java">Depth-First Search (Backtracking)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">988</td>
    <td><a href="https://leetcode.com/problems/smallest-string-starting-from-leaf/">Smallest String Starting From Leaf</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1026</td>
    <td><a href="https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/">Maximum Difference Between Node and Ancestor</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1457</td>
    <td><a href="https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/">Pseudo-Palindromic Paths in a Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_BFS.java"><em>Breadth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1971</td>
    <td><a href="https://leetcode.com/problems/find-if-path-exists-in-graph/">Find if Path Exists in Graph</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_BFS.java"><em>Breadth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_UnionFind.java"><em>Union Find</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2359</td>
    <td><a href="https://leetcode.com/problems/find-closest-node-to-given-two-nodes/">Find Closest Node to Given Two Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2359.%20Find%20Closest%20Node%20to%20Given%20Two%20Nodes/FindClosestNodeToGivenTwoNodes_DFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="design">Design</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">225</td>
    <td><a href="https://leetcode.com/problems/implement-stack-using-queues/">Implement Stack using Queues</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/225.%20Implement%20Stack%20using%20Queues/ImplementStackUsingQueues.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">232</td>
    <td><a href="https://leetcode.com/problems/implement-queue-using-stacks/">Implement Queue using Stacks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/232.%20Implement%20Queue%20using%20Stacks/ImplementQueueUsingStacks.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">295</td>
    <td><a href="https://leetcode.com/problems/find-median-from-data-stream/">Find Median from Data Stream</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/295.%20Find%20Median%20from%20Data%20Stream/MedianFinder_PriorityQueue.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#data-stream">Data Stream</a>,
      <a href="#design">Design</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">707</td>
    <td><a href="https://leetcode.com/problems/design-linked-list/">Design Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/707.%20Design%20Linked%20List/SinglyLinkedList.java">Singly Linked List</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/707.%20Design%20Linked%20List/DoublyLinkedList.java">Doubly Linked List</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#linked-list">Linked List</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1603</td>
    <td><a href="https://leetcode.com/problems/design-parking-system/">Design Parking System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1603.%20Design%20Parking%20System/ParkingSystem.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#design">Design</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1865</td>
    <td><a href="https://leetcode.com/problems/finding-pairs-with-a-certain-sum/">Finding Pairs With a Certain Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1865.%20Finding%20Pairs%20With%20a%20Certain%20Sum/FindingPairsWithACertainSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#design">Design</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="divide-and-conquer">Divide and Conquer</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">169</td>
    <td><a href="https://leetcode.com/problems/majority-element/">Majority Element</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_DivideAndConquer_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#divide-and-conquer">Divide and Conquer</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_HashTable_Counting.java"><em>Counting & Hash Table</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="dynamic-programming">Dynamic Programming</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">5</td>
    <td><a href="https://leetcode.com/problems/longest-palindromic-substring/">Longest Palindromic Substring</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using Two Pointers with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_TwoPointers1.java"><em>Approach 1</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_TwoPointers2.java"><em>Approach 2</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">45</td>
    <td><a href="https://leetcode.com/problems/jump-game-ii/">Jump Game II</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Memoization.java">Memoization</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Tabulation.java">Tabulation</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_Greedy.java"><em>Greedy</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">55</td>
    <td><a href="https://leetcode.com/problems/jump-game/">Jump Game</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_Greedy.java"><em>Greedy</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">70</td>
    <td><a href="https://leetcode.com/problems/climbing-stairs/">Climbing Stairs</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">121</td>
    <td><a href="https://leetcode.com/problems/best-time-to-buy-and-sell-stock/">Best Time to Buy and Sell Stock</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/121.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock/BestTimeToBuyAndSellStock_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/121.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock/BestTimeToBuyAndSellStock.java"><em>without Using Dynamic Programming</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">152</td>
    <td><a href="https://leetcode.com/problems/maximum-product-subarray/">Maximum Product Subarray</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/152.%20Maximum%20Product%20Subarray/MaximumProductSubarray_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/152.%20Maximum%20Product%20Subarray/MaximumProductSubarray.java"><em>Array</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">264</td>
    <td><a href="https://leetcode.com/problems/ugly-number-ii/">Ugly Number II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#math">Math</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_PriorityQueue.java"><em>Heap (Priority Queue)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">368</td>
    <td><a href="https://leetcode.com/problems/largest-divisible-subset/">Largest Divisible Subset</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/368.%20Largest%20Divisible%20Subset/LargestDivisibleSubset.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">509</td>
    <td><a href="https://leetcode.com/problems/fibonacci-number/">Fibonacci Number</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">746</td>
    <td><a href="https://leetcode.com/problems/min-cost-climbing-stairs/">Min Cost Climbing Stairs</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/746.%20Min%20Cost%20Climbing%20Stairs/MinCostClimbingStairs_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/746.%20Min%20Cost%20Climbing%20Stairs/MinCostClimbingStairs_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1137</td>
    <td><a href="https://leetcode.com/problems/n-th-tribonacci-number/">N-th Tribonacci Number</a></td>
    <td align="center">Java with Dynamic Programming
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Iterative.java">Iteratively</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Recursive.java">Recursively (Memoization)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1155</td>
    <td><a href="https://leetcode.com/problems/number-of-dice-rolls-with-target-sum/">Number of Dice Rolls With Target Sum</a></td>
    <td align="center">Java with Dynamic Programming using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1155.%20Number%20of%20Dice%20Rolls%20With%20Target%20Sum/NumberOfDiceRollsWithTargetSum_Memoization.java">Memoization</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1155.%20Number%20of%20Dice%20Rolls%20With%20Target%20Sum/NumberOfDiceRollsWithTargetSum_Tabulation.java">Tabulation</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1578</td>
    <td><a href="https://leetcode.com/problems/minimum-time-to-make-rope-colorful/">Minimum Time to Make Rope Colorful</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_DynamicProgramming.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_Greedy.java"><em>Greedy</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="enumeration">Enumeration</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">1534</td>
    <td><a href="https://leetcode.com/problems/count-good-triplets/">Count Good Triplets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1534.%20Count%20Good%20Triplets/CountGoodTriplets.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#enumeration">Enumeration</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1995</td>
    <td><a href="https://leetcode.com/problems/count-special-quadruplets/">Count Special Quadruplets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1995.%20Count%20Special%20Quadruplets/CountSpecialQuadruplets.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#enumeration">Enumeration</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1995.%20Count%20Special%20Quadruplets/CountSpecialQuadruplets_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2240</td>
    <td><a href="https://leetcode.com/problems/number-of-ways-to-buy-pens-and-pencils/">Number of Ways to Buy Pens and Pencils</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2240.%20Number%20of%20Ways%20to%20Buy%20Pens%20and%20Pencils/NumberOfWaysToBuyPensAndPencils.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#enumeration">Enumeration</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2437</td>
    <td><a href="https://leetcode.com/problems/number-of-valid-clock-times/">Number of Valid Clock Times</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2437.%20Number%20of%20Valid%20Clock%20Times/NumberOfValidClockTimes.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#enumeration">Enumeration</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="geometry">Geometry</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">223</td>
    <td><a href="https://leetcode.com/problems/rectangle-area/">Rectangle Area</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/223.%20Rectangle%20Area/RectangleArea.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">593</td>
    <td><a href="https://leetcode.com/problems/valid-square/">Valid Square</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/593.%20Valid%20Square/ValidSquare.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">812</td>
    <td><a href="https://leetcode.com/problems/largest-triangle-area/">Largest Triangle Area</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/812.%20Largest%20Triangle%20Area/LargestTriangleArea.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">836</td>
    <td><a href="https://leetcode.com/problems/rectangle-overlap/">Rectangle Overlap</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/836.%20Rectangle%20Overlap/RectangleOverlap.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1037</td>
    <td><a href="https://leetcode.com/problems/valid-boomerang/">Valid Boomerang</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1037.%20Valid%20Boomerang/ValidBoomerang.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1232</td>
    <td><a href="https://leetcode.com/problems/check-if-it-is-a-straight-line/">Check If It Is a Straight Line</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1232.%20Check%20If%20It%20Is%20a%20Straight%20Line/CheckIfItIsAStraightLine.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="graph">Graph</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">797</td>
    <td><a href="https://leetcode.com/problems/all-paths-from-source-to-target/">All Paths From Source to Target</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive_Backtracking.java">Depth-First Search (Backtracking)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/797.%20All%20Paths%20From%20Source%20to%20Target/AllPathsFromSourceToTarget_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1971</td>
    <td><a href="https://leetcode.com/problems/find-if-path-exists-in-graph/">Find if Path Exists in Graph</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Iterative.java">Depth-First Search (Iterative)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Recursive.java">Depth-First Search (Recursive)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_UnionFind.java">Union Find</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2359</td>
    <td><a href="https://leetcode.com/problems/find-closest-node-to-given-two-nodes/">Find Closest Node to Given Two Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2359.%20Find%20Closest%20Node%20to%20Given%20Two%20Nodes/FindClosestNodeToGivenTwoNodes_DFS.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="greedy">Greedy</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">45</td>
    <td><a href="https://leetcode.com/problems/jump-game-ii/">Jump Game II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Memoization.java"><em>Dynamic Programming (Memoization)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/45.%20Jump%20Game%20II/JumpGameII_DynamicProgramming_Tabulation.java"><em>Dynamic Programming (Tabulation)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">55</td>
    <td><a href="https://leetcode.com/problems/jump-game/">Jump Game</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/55.%20Jump%20Game/JumpGame_DynamicProgramming.java"><em>Dynamic Programming</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">134</td>
    <td><a href="https://leetcode.com/problems/gas-station/">Gas Station</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/134.%20Gas%20Station/GasStation.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">334</td>
    <td><a href="https://leetcode.com/problems/increasing-triplet-subsequence/">Increasing Triplet Subsequence</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/334.%20Increasing%20Triplet%20Subsequence/IncreasingTripletSubsequence.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">561</td>
    <td><a href="https://leetcode.com/problems/array-partition/">Array Partition</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_CountingSort_Greedy.java">Greedy & Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_Sorting_Greedy.java">Greedy & Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">948</td>
    <td><a href="https://leetcode.com/problems/bag-of-tokens/">Bag of Tokens</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/948.%20Bag%20of%20Tokens/BagOfTokens.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">976</td>
    <td><a href="https://leetcode.com/problems/largest-perimeter-triangle/">Largest Perimeter Triangle</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/976.%20Largest%20Perimeter%20Triangle/LargestPerimeterTriangle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1323</td>
    <td><a href="https://leetcode.com/problems/maximum-69-number/">Maximum 69 Number</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1323.%20Maximum%2069%20Number/Maximum69Number_Math.java">Math</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1323.%20Maximum%2069%20Number/Maximum69Number_String.java">String</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1328</td>
    <td><a href="https://leetcode.com/problems/break-a-palindrome/">Break a Palindrome</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1328.%20Break%20a%20Palindrome/BreakAPalindrome.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1578</td>
    <td><a href="https://leetcode.com/problems/minimum-time-to-make-rope-colorful/">Minimum Time to Make Rope Colorful</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_Greedy.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_DynamicProgramming.java"><em>Dynamic Programming</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1775</td>
    <td><a href="https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/">Equal Sum Arrays With Minimum Number of Operations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1775.%20Equal%20Sum%20Arrays%20With%20Minimum%20Number%20of%20Operations/EqualSumArraysWithMinimumNumberOfOperations_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1833</td>
    <td><a href="https://leetcode.com/problems/maximum-ice-cream-bars/">Maximum Ice Cream Bars</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1833.%20Maximum%20Ice%20Cream%20Bars/MaximumIceCreamBars.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2007</td>
    <td><a href="https://leetcode.com/problems/find-original-array-from-doubled-array/">Find Original Array From Doubled Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_HashMap_Sorting.java">Hash Table</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Queue_Sorting.java">Queue</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Counting.java">Counting Array</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2131</td>
    <td><a href="https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/">Longest Palindrome by Concatenating Two Letter Words</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2136</td>
    <td><a href="https://leetcode.com/problems/earliest-possible-day-of-full-bloom/">Earliest Possible Day of Full Bloom</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2136.%20Earliest%20Possible%20Day%20of%20Full%20Bloom/EarliestPossibleDayOfFullBloom.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2244</td>
    <td><a href="https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks/">Minimum Rounds to Complete All Tasks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2244.%20Minimum%20Rounds%20to%20Complete%20All%20Tasks/MinimumRoundsToCompleteAllTasks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2279</td>
    <td><a href="https://leetcode.com/problems/maximum-bags-with-full-capacity-of-rocks/">Maximum Bags With Full Capacity of Rocks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2279.%20Maximum%20Bags%20With%20Full%20Capacity%20of%20Rocks/MaximumBagsWithFullCapacityOfRocks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2389</td>
    <td><a href="https://leetcode.com/problems/longest-subsequence-with-limited-sum/">Longest Subsequence With Limited Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2389.%20Longest%20Subsequence%20With%20Limited%20Sum/LongestSubsequenceWithLimitedSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#prefix-sum">Prefix Sum</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="hash-table">Hash Table</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">1</td>
    <td><a href="https://leetcode.com/problems/two-sum/">Two Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1.%20Two%20Sum/TwoSum_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">3</td>
    <td><a href="https://leetcode.com/problems/longest-substring-without-repeating-characters/">Longest Substring Without Repeating Characters</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters.java">without Using Hash Table</a>
    </td>
  </tr>
  <tr>
    <td align="center">12</td>
    <td><a href="https://leetcode.com/problems/integer-to-roman/">Integer to Roman</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_WithoutHashTable.java"><em>without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">13</td>
    <td><a href="https://leetcode.com/problems/roman-to-integer/">Roman to Integer</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_HashMap.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_WithoutHashMap.java"><em>without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">36</td>
    <td><a href="https://leetcode.com/problems/valid-sudoku/">Valid Sudoku</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku.java"><em>without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">49</td>
    <td><a href="https://leetcode.com/problems/group-anagrams/">Group Anagrams</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/49.%20Group%20Anagrams/GroupAnagrams.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">73</td>
    <td><a href="https://leetcode.com/problems/set-matrix-zeroes/">Set Matrix Zeroes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_Array.java">Array</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_InPlace.java">In-Place</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">169</td>
    <td><a href="https://leetcode.com/problems/majority-element/">Majority Element</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_HashTable_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#divide-and-conquer">Divide and Conquer</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_DivideAndConquer_Counting.java"><em>Counting & Divide and Conquer</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">205</td>
    <td><a href="https://leetcode.com/problems/isomorphic-strings/">Isomorphic Strings</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/205.%20Isomorphic%20Strings/IsomorphicStrings.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">217</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate/">Contains Duplicate</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashMap.java">Hash Map</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashSet.java">Hash Set</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">219</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-ii/">Contains Duplicate II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_HashMap.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_SlidingWindow.java"><em>Sliding Window</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">229</td>
    <td><a href="https://leetcode.com/problems/majority-element-ii/">Majority Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_HashTable_Counting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">264</td>
    <td><a href="https://leetcode.com/problems/ugly-number-ii/">Ugly Number II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_DynamicProgramming.java">Dynamic Programming</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_PriorityQueue.java">Heap (Priority Queue)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">290</td>
    <td><a href="https://leetcode.com/problems/word-pattern/">Word Pattern</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/290.%20Word%20Pattern/WordPattern.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">383</td>
    <td><a href="https://leetcode.com/problems/ransom-note/">Ransom Note</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_Counting.java"><em>Counting Array</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">438</td>
    <td><a href="https://leetcode.com/problems/find-all-anagrams-in-a-string/">Find All Anagrams in a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/438.%20Find%20All%20Anagrams%20in%20a%20String/FindAllAnagramsInAString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">448</td>
    <td><a href="https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/">Find All Numbers Disappeared in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/448.%20Find%20All%20Numbers%20Disappeared%20in%20an%20Array/FindAllNumbersDisappearedInAnArray_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/448.%20Find%20All%20Numbers%20Disappeared%20in%20an%20Array/FindAllNumbersDisappearedInAnArray.java"><em>without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">496</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-i/">Next Greater Element I</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/496.%20Next%20Greater%20Element%20I/NextGreaterElementI_HashTable_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">523</td>
    <td><a href="https://leetcode.com/problems/continuous-subarray-sum/">Continuous Subarray Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/523.%20Continuous%20Subarray%20Sum/ContinuousSubarraySum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">560</td>
    <td><a href="https://leetcode.com/problems/subarray-sum-equals-k/">Subarray Sum Equals K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/560.%20Subarray%20Sum%20Equals%20K/SubarraySumEqualsK.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">567</td>
    <td><a href="https://leetcode.com/problems/permutation-in-string/">Permutation in String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/567.%20Permutation%20in%20String/PermutationInString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">609</td>
    <td><a href="https://leetcode.com/problems/find-duplicate-file-in-system/">Find Duplicate File in System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/609.%20Find%20Duplicate%20File%20in%20System/FindDuplicateFileInSystem_HashMap.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">645</td>
    <td><a href="https://leetcode.com/problems/set-mismatch/">Set Mismatch</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_BitManipulation.java"><em>Bit Manipulation</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java"><em>Breadth-First Search (without Hash Table)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java"><em>Two Pointers (with Iterative Inorder Traversal)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java"><em>Two Pointers (with Recursive Inorder Traversal)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">904</td>
    <td><a href="https://leetcode.com/problems/fruit-into-baskets/">Fruit Into Baskets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/904.%20Fruit%20Into%20Baskets/FruitIntoBaskets.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">923</td>
    <td><a href="https://leetcode.com/problems/3sum-with-multiplicity/">3Sum With Multiplicity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Counting.java"><em>Counting</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Sorting_TwoPointers.java"><em>Sorting & Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">929</td>
    <td><a href="https://leetcode.com/problems/unique-email-addresses/">Unique Email Addresses</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/929.%20Unique%20Email%20Addresses/UniqueEmailAddresses_HashSet.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">953</td>
    <td><a href="https://leetcode.com/problems/verifying-an-alien-dictionary/">Verifying an Alien Dictionary</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/953.%20Verifying%20an%20Alien%20Dictionary/VerifyingAnAlienDictionary.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">974</td>
    <td><a href="https://leetcode.com/problems/subarray-sums-divisible-by-k/">Subarray Sums Divisible by K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_Counting.java"><em>Counting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1122</td>
    <td><a href="https://leetcode.com/problems/relative-sort-array/">Relative Sort Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_CountingSort_Sorting.java"><em>Counting Sort</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1207</td>
    <td><a href="https://leetcode.com/problems/unique-number-of-occurrences/">Unique Number of Occurrences</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1207.%20Unique%20Number%20of%20Occurrences/UniqueNumberOfOccurrences_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1207.%20Unique%20Number%20of%20Occurrences/UniqueNumberOfOccurrences_Counting_Sorting.java"><em>Counting & Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1346</td>
    <td><a href="https://leetcode.com/problems/check-if-n-and-its-double-exist/">Check If N and Its Double Exist</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_Sorting_BinarySearch.java"><em>Binary Search & Sorting</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1497</td>
    <td><a href="https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k/">Check If Array Pairs Are Divisible by k</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1497.%20Check%20If%20Array%20Pairs%20Are%20Divisible%20by%20k/CheckIfArrayPairsAreDivisibleByK_Counting.java"><em>Counting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1636</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-increasing-frequency/">Sort Array by Increasing Frequency</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1636.%20Sort%20Array%20by%20Increasing%20Frequency/SortArrayByIncreasingFrequency.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1657</td>
    <td><a href="https://leetcode.com/problems/determine-if-two-strings-are-close/">Determine if Two Strings Are Close</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting_HashTable.java">Hash Table & Sorting</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting.java"><em>only Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1679</td>
    <td><a href="https://leetcode.com/problems/max-number-of-k-sum-pairs/">Max Number of K-Sum Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_Sorting_TwoPointers.java"><em>Sorting & Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1711</td>
    <td><a href="https://leetcode.com/problems/count-good-meals/">Count Good Meals</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1711.%20Count%20Good%20Meals/CountGoodMeals.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1814</td>
    <td><a href="https://leetcode.com/problems/count-nice-pairs-in-an-array/">Count Nice Pairs in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1814.%20Count%20Nice%20Pairs%20in%20an%20Array/CountNicePairsInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1832</td>
    <td><a href="https://leetcode.com/problems/check-if-the-sentence-is-pangram/">Check if the Sentence is Pangram</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_HashSet.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_BitManipulation.java"><em>Bit Manipulation</em></a> ,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_Counting.java"><em>Counting</em></a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram.java"><em>Without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1865</td>
    <td><a href="https://leetcode.com/problems/finding-pairs-with-a-certain-sum/">Finding Pairs With a Certain Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1865.%20Finding%20Pairs%20With%20a%20Certain%20Sum/FindingPairsWithACertainSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#design">Design</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1935</td>
    <td><a href="https://leetcode.com/problems/maximum-number-of-words-you-can-type/">Maximum Number of Words You Can Type</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1935.%20Maximum%20Number%20of%20Words%20You%20Can%20Type/MaximumNumberOfWordsYouCanType.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2006</td>
    <td><a href="https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/">Count Number of Pairs With Absolute Difference K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK.java"><em>Brute Force</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2006.%20Count%20Number%20of%20Pairs%20With%20Absolute%20Difference%20K/CountNumberOfPairsWithAbsoluteDifferenceK_Counting.java"><em>Counting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2007</td>
    <td><a href="https://leetcode.com/problems/find-original-array-from-doubled-array/">Find Original Array From Doubled Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_HashMap_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Queue_Sorting.java"><em>Queue</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Counting.java"><em>Counting Array</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2131</td>
    <td><a href="https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/">Longest Palindrome by Concatenating Two Letter Words</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_Counting.java"><em>Counting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2133</td>
    <td><a href="https://leetcode.com/problems/check-if-every-row-and-column-contains-all-numbers/">Check if Every Row and Column Contains All Numbers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers.java"><em>Without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2244</td>
    <td><a href="https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks/">Minimum Rounds to Complete All Tasks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2244.%20Minimum%20Rounds%20to%20Complete%20All%20Tasks/MinimumRoundsToCompleteAllTasks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2351</td>
    <td><a href="https://leetcode.com/problems/first-letter-to-appear-twice/">First Letter to Appear Twice</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_Counting.java"><em>Counting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2352</td>
    <td><a href="https://leetcode.com/problems/equal-row-and-column-pairs/">Equal Row and Column Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2352.%20Equal%20Row%20and%20Column%20Pairs/EqualRowAndColumnPairs.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2395</td>
    <td><a href="https://leetcode.com/problems/find-subarrays-with-equal-sum/">Find Subarrays With Equal Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2395.%20Find%20Subarrays%20With%20Equal%20Sum/FindSubarraysWithEqualSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2399</td>
    <td><a href="https://leetcode.com/problems/check-distances-between-same-letters/">Check Distances Between Same Letters</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters.java"><em>Without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2451</td>
    <td><a href="https://leetcode.com/problems/odd-string-difference/">Odd String Difference</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference.java"><em>Without Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2453</td>
    <td><a href="https://leetcode.com/problems/destroy-sequential-targets/">Destroy Sequential Targets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2453.%20Destroy%20Sequential%20Targets/DestroySequentialTargets_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="heap-priority-queue">Heap (Priority Queue)</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">264</td>
    <td><a href="https://leetcode.com/problems/ugly-number-ii/">Ugly Number II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_PriorityQueue.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#math">Math</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_DynamicProgramming.java"><em>Dynamic Programming</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">295</td>
    <td><a href="https://leetcode.com/problems/find-median-from-data-stream/">Find Median from Data Stream</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/295.%20Find%20Median%20from%20Data%20Stream/MedianFinder_PriorityQueue.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#data-stream">Data Stream</a>,
      <a href="#design">Design</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1337</td>
    <td><a href="https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/">The K Weakest Rows in a Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_PriorityQueue.java">Heap (Priority Queue) & Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix.java"><em>Linear Search</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch.java">Binary Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_Sorting.java"><em>Sorting & Binary Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1834</td>
    <td><a href="https://leetcode.com/problems/single-threaded-cpu/">Single-Threaded CPU</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1834.%20Single-Threaded%20CPU/SingleThreadedCPU.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1962</td>
    <td><a href="https://leetcode.com/problems/remove-stones-to-minimize-the-total/">Remove Stones to Minimize the Total</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1962.%20Remove%20Stones%20to%20Minimize%20the%20Total/RemoveStonesToMinimizeTheTotal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="interactive">Interactive</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">374</td>
    <td><a href="https://leetcode.com/problems/guess-number-higher-or-lower/">Guess Number Higher or Lower</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/374.%20Guess%20Number%20Higher%20or%20Lower/GuessNumberHigherOrLower_BinarySearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#interactive">Interactive</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="linked-list">Linked List</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">19</td>
    <td><a href="https://leetcode.com/problems/remove-nth-node-from-end-of-list/">Remove Nth Node From End of List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/19.%20Remove%20Nth%20Node%20From%20End%20of%20List/RemoveNthNodeFromEndOfList_OnePass.java">One Pass</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/19.%20Remove%20Nth%20Node%20From%20End%20of%20List/RemoveNthNodeFromEndOfList_TwoPasses.java">Two Passes</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">24</td>
    <td><a href="https://leetcode.com/problems/swap-nodes-in-pairs/">Swap Nodes in Pairs</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/24.%20Swap%20Nodes%20in%20Pairs/SwapNodesInPairs.java">Iteration</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/24.%20Swap%20Nodes%20in%20Pairs/SwapNodesInPairs.java">Recursion</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">92</td>
    <td><a href="https://leetcode.com/problems/reverse-linked-list-ii/">Reverse Linked List II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/92.%20Reverse%20Linked%20List%20II/ReverseLinkedListII.java">Java</a>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">114</td>
    <td><a href="https://leetcode.com/problems/flatten-binary-tree-to-linked-list/">Flatten Binary Tree to Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">206</td>
    <td><a href="https://leetcode.com/problems/reverse-linked-list/">Reverse Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList.java">Array List</a>, Reverse Nodes
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList.java">Iteratively</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList_Recursive.java">Recursively</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">707</td>
    <td><a href="https://leetcode.com/problems/design-linked-list/">Design Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/707.%20Design%20Linked%20List/SinglyLinkedList.java">Singly Linked List</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/707.%20Design%20Linked%20List/DoublyLinkedList.java">Doubly Linked List</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#linked-list">Linked List</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">876</td>
    <td><a href="https://leetcode.com/problems/middle-of-the-linked-list/">Middle of the Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/876.%20Middle%20of%20the%20Linked%20List/MiddleOfTheLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1019</td>
    <td><a href="https://leetcode.com/problems/next-greater-node-in-linked-list/">Next Greater Node In Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1019.%20Next%20Greater%20Node%20In%20Linked%20List/NextGreaterNodeInLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2095</td>
    <td><a href="https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list/">Delete the Middle Node of a Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2095.%20Delete%20the%20Middle%20Node%20of%20a%20Linked%20List/DeleteTheMiddleNodeOfALinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2130</td>
    <td><a href="https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/">Maximum Twin Sum of a Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers.java">Two Pointers</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers_Stack.java">Two Pointers & Stack</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="math">Math</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">12</td>
    <td><a href="https://leetcode.com/problems/integer-to-roman/">Integer to Roman</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_HashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_WithoutHashTable.java">without Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">13</td>
    <td><a href="https://leetcode.com/problems/roman-to-integer/">Roman to Integer</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_HashMap.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_WithoutHashMap.java">without Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">29</td>
    <td><a href="https://leetcode.com/problems/divide-two-integers/">Divide Two Integers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/29.%20Divide%20Two%20Integers/DivideTwoIntegers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">70</td>
    <td><a href="https://leetcode.com/problems/climbing-stairs/">Climbing Stairs</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Iterative.java">Tabulation</a><a> or </a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">223</td>
    <td><a href="https://leetcode.com/problems/rectangle-area/">Rectangle Area</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/223.%20Rectangle%20Area/RectangleArea.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">263</td>
    <td><a href="https://leetcode.com/problems/ugly-number/">Ugly Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/263.%20Ugly%20Number/UglyNumber.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">264</td>
    <td><a href="https://leetcode.com/problems/ugly-number-ii/">Ugly Number II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_DynamicProgramming.java">Dynamic Programming</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/264.%20Ugly%20Number%20II/UglyNumberII_PriorityQueue.java">Heap (Priority Queue)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">368</td>
    <td><a href="https://leetcode.com/problems/largest-divisible-subset/">Largest Divisible Subset</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/368.%20Largest%20Divisible%20Subset/LargestDivisibleSubset.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">371</td>
    <td><a href="https://leetcode.com/problems/sum-of-two-integers/">Sum of Two Integers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/371.%20Sum%20of%20Two%20Integers/SumOfTwoIntegers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">412</td>
    <td><a href="https://leetcode.com/problems/fizz-buzz/">Fizz Buzz</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/412.%20Fizz%20Buzz/FizzBuzz.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">492</td>
    <td><a href="https://leetcode.com/problems/construct-the-rectangle/">Construct the Rectangle</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/492.%20Construct%20the%20Rectangle/ConstructTheRectangle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">509</td>
    <td><a href="https://leetcode.com/problems/fibonacci-number/">Fibonacci Number</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Iterative.java">Tabulation</a><a> or </a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">523</td>
    <td><a href="https://leetcode.com/problems/continuous-subarray-sum/">Continuous Subarray Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/523.%20Continuous%20Subarray%20Sum/ContinuousSubarraySum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">556</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iii/">Next Greater Element III</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/556.%20Next%20Greater%20Element%20III/NextGreaterElementIII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">593</td>
    <td><a href="https://leetcode.com/problems/valid-square/">Valid Square</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/593.%20Valid%20Square/ValidSquare.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">812</td>
    <td><a href="https://leetcode.com/problems/largest-triangle-area/">Largest Triangle Area</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/812.%20Largest%20Triangle%20Area/LargestTriangleArea.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">836</td>
    <td><a href="https://leetcode.com/problems/rectangle-overlap/">Rectangle Overlap</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/836.%20Rectangle%20Overlap/RectangleOverlap.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">976</td>
    <td><a href="https://leetcode.com/problems/largest-perimeter-triangle/">Largest Perimeter Triangle</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/976.%20Largest%20Perimeter%20Triangle/LargestPerimeterTriangle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">989</td>
    <td><a href="https://leetcode.com/problems/add-to-array-form-of-integer/">Add to Array-Form of Integer</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/989.%20Add%20to%20Array-Form%20of%20Integer/AddToArrayFormOfInteger.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1033</td>
    <td><a href="https://leetcode.com/problems/moving-stones-until-consecutive/">Moving Stones Until Consecutive</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1033.%20Moving%20Stones%20Until%20Consecutive/MovingStonesUntilConsecutive.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#brainteaser">Brainteaser</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1037</td>
    <td><a href="https://leetcode.com/problems/valid-boomerang/">Valid Boomerang</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1037.%20Valid%20Boomerang/ValidBoomerang.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1071</td>
    <td><a href="https://leetcode.com/problems/greatest-common-divisor-of-strings/">Greatest Common Divisor of Strings</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1071.%20Greatest%20Common%20Divisor%20of%20Strings/GreatestCommonDivisorOfStrings.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1103</td>
    <td><a href="https://leetcode.com/problems/distribute-candies-to-people/">Distribute Candies to People</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1103.%20Distribute%20Candies%20to%20People/DistributeCandiesToPeople.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1137</td>
    <td><a href="https://leetcode.com/problems/n-th-tribonacci-number/">N-th Tribonacci Number</a></td>
    <td align="center">Java with Dynamic Programming
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Iterative.java">Iteratively</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Recursive.java">Recursively (Memoization)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1154</td>
    <td><a href="https://leetcode.com/problems/day-of-the-year/">Day of the Year</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1154.%20Day%20of%20the%20Year/DayOfTheYear.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1232</td>
    <td><a href="https://leetcode.com/problems/check-if-it-is-a-straight-line/">Check If It Is a Straight Line</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1232.%20Check%20If%20It%20Is%20a%20Straight%20Line/CheckIfItIsAStraightLine.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#geometry">Geometry</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1323</td>
    <td><a href="https://leetcode.com/problems/maximum-69-number/">Maximum 69 Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1323.%20Maximum%2069%20Number/Maximum69Number_Math.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1323.%20Maximum%2069%20Number/Maximum69Number_String.java"><em>String</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1342</td>
    <td><a href="https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/">Number of Steps to Reduce a Number to Zero</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1342.%20Numbers%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero/NumberOfStepsToReduceANumberToZero_Math.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1342.%20Numbers%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero/NumberOfStepsToReduceANumberToZero_BitManipulation.java"><em>Bit Manipulation</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1486</td>
    <td><a href="https://leetcode.com/problems/xor-operation-in-an-array/">XOR Operation in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1486.%20XOR%20Operation%20in%20an%20Array/XOROperationInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1523</td>
    <td><a href="https://leetcode.com/problems/count-odd-numbers-in-an-interval-range/">Count Odd Numbers in an Interval Range</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1523.%20Count%20Odd%20Numbers%20in%20an%20Interval%20Range/CountOddNumbersInAnIntervalRange.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1680</td>
    <td><a href="https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers/">Concatenation of Consecutive Binary Numbers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_Math.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_BitManipulation.java"><em>Bit Manipulation</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1814</td>
    <td><a href="https://leetcode.com/problems/count-nice-pairs-in-an-array/">Count Nice Pairs in an Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1814.%20Count%20Nice%20Pairs%20in%20an%20Array/CountNicePairsInAnArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1979</td>
    <td><a href="https://leetcode.com/problems/find-greatest-common-divisor-of-array/">Find Greatest Common Divisor of Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1979.%20Find%20Greatest%20Common%20Divisor%20of%20Array/FindGreatestCommonDivisorOfArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#number-theory">Number Theory</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2028</td>
    <td><a href="https://leetcode.com/problems/find-missing-observations/">Find Missing Observations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2028.%20Find%20Missing%20Observations/FindMissingObservations.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2169</td>
    <td><a href="https://leetcode.com/problems/count-operations-to-obtain-zero/">Count Operations to Obtain Zero</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2169.%20Count%20Operations%20to%20Obtain%20Zero/CountOperationsToObtainZero.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2240</td>
    <td><a href="https://leetcode.com/problems/number-of-ways-to-buy-pens-and-pencils/">Number of Ways to Buy Pens and Pencils</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2240.%20Number%20of%20Ways%20to%20Buy%20Pens%20and%20Pencils/NumberOfWaysToBuyPensAndPencils.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#enumeration">Enumeration</a>,
      <a href="#math">Math</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2413</td>
    <td><a href="https://leetcode.com/problems/smallest-even-multiple/">Smallest Even Multiple</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2413.%20Smallest%20Even%20Multiple/SmallestEvenMultiple.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#number-theory">Number Theory</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2451</td>
    <td><a href="https://leetcode.com/problems/odd-string-difference/">Odd String Difference</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="matrix">Matrix</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">36</td>
    <td><a href="https://leetcode.com/problems/valid-sudoku/">Valid Sudoku</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/36.%20Valid%20Sudoku/ValidSudoku_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">37</td>
    <td><a href="https://leetcode.com/problems/sudoku-solver/">Sudoku Solver</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/37.%20Sudoku%20Solver/SudokuSolver.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">73</td>
    <td><a href="https://leetcode.com/problems/set-matrix-zeroes/">Set Matrix Zeroes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_Array.java">Array</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_HashTable.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/73.%20Set%20Matrix%20Zeroes/SetMatrixZeroes_InPlace.java">In-Place</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">79</td>
    <td><a href="https://leetcode.com/problems/word-search/">Word Search</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/79.%20Word%20Search/WordSearch.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">130</td>
    <td><a href="https://leetcode.com/problems/surrounded-regions/">Surrounded Regions</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_DFS.java">Depth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_UnionFind.java">Union Find</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">200</td>
    <td><a href="https://leetcode.com/problems/number-of-islands/">Number of Islands</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_DFS.java">Depth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_UnionFind.java">Union Find</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">766</td>
    <td><a href="https://leetcode.com/problems/toeplitz-matrix/">Toeplitz Matrix</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td>Follow up:
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix_OneRowAtATime.java">One Row at a Time</a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/766.%20Toeplitz%20Matrix/ToeplitzMatrix_OneColumnAtATime.java">One Column at a Time</a>
    </td>
  </tr>
  <tr>
    <td align="center">835</td>
    <td><a href="https://leetcode.com/problems/image-overlap/">Image Overlap</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/835.%20Image%20Overlap/ImageOverlap_BitManipulation.java">Bit Manipulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/835.%20Image%20Overlap/ImageOverlap_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1337</td>
    <td><a href="https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/">The K Weakest Rows in a Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix.java">Linear Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch.java">Binary Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_PriorityQueue.java">Heap (Priority Queue)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1351</td>
    <td><a href="https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix/">Count Negative Numbers in a Sorted Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix.java">Linear Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1351.%20Count%20Negative%20Numbers%20in%20a%20Sorted%20Matrix/CountNegativeNumbersInASortedMatrix_BinarySearch.java">Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1672</td>
    <td><a href="https://leetcode.com/problems/richest-customer-wealth/">Richest Customer Wealth</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1672.%20Richest%20Customer%20Wealth/RichestCustomerWealth.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1926</td>
    <td><a href="https://leetcode.com/problems/nearest-exit-from-entrance-in-maze/">Nearest Exit from Entrance in Maze</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1926.%20Nearest%20Exit%20from%20Entrance%20in%20Maze/NearestExitFromEntranceInMaze.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2133</td>
    <td><a href="https://leetcode.com/problems/check-if-every-row-and-column-contains-all-numbers/">Check if Every Row and Column Contains All Numbers</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2133.%20Check%20if%20Every%20Row%20and%20Column%20Contains%20All%20Numbers/CheckIfEveryRowAndColumnContainsAllNumbers_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2352</td>
    <td><a href="https://leetcode.com/problems/equal-row-and-column-pairs/">Equal Row and Column Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2352.%20Equal%20Row%20and%20Column%20Pairs/EqualRowAndColumnPairs.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="memoization">Memoization</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">70</td>
    <td><a href="https://leetcode.com/problems/climbing-stairs/">Climbing Stairs</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/70.%20Climbing%20Stairs/ClimbingStairs_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">509</td>
    <td><a href="https://leetcode.com/problems/fibonacci-number/">Fibonacci Number</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1137</td>
    <td><a href="https://leetcode.com/problems/n-th-tribonacci-number/">N-th Tribonacci Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Recursive.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1137.%20N-th%20Tribonacci%20Number/NthTribonacciNumber_Iterative.java"><em>Dynamic Programming (Iterative)</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="monotonic-stack">Monotonic Stack</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">496</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-i/">Next Greater Element I</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/496.%20Next%20Greater%20Element%20I/NextGreaterElementI_HashTable_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">503</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-ii/">Next Greater Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/503.%20Next%20Greater%20Element%20II/NextGreaterElementII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1019</td>
    <td><a href="https://leetcode.com/problems/next-greater-node-in-linked-list/">Next Greater Node In Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1019.%20Next%20Greater%20Node%20In%20Linked%20List/NextGreaterNodeInLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2454</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iv/">Next Greater Element IV</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2454.%20Next%20Greater%20Element%20IV/NextGreaterElementIV_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="number-theory">Number Theory</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">1979</td>
    <td><a href="https://leetcode.com/problems/find-greatest-common-divisor-of-array/">Find Greatest Common Divisor of Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1979.%20Find%20Greatest%20Common%20Divisor%20of%20Array/FindGreatestCommonDivisorOfArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#number-theory">Number Theory</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2413</td>
    <td><a href="https://leetcode.com/problems/smallest-even-multiple/">Smallest Even Multiple</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2413.%20Smallest%20Even%20Multiple/SmallestEvenMultiple.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#number-theory">Number Theory</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="ordered-set">Ordered Set</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">220</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-iii/">Contains Duplicate III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_TreeSet_OrderedSet.java">Sliding Window & Ordered Set</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bucket-sort">Bucket Sort</a>,
      <a href="#ordered-set">Ordered Set</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_HashMap_BucketSort.java"><em>Sliding Window & Bucket Sort</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="prefix-sum">Prefix Sum</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">238</td>
    <td><a href="https://leetcode.com/problems/product-of-array-except-self/">Product of Array Except Self</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/238.%20Product%20of%20Array%20Except%20Self/ProductOfArrayExceptSelf.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">523</td>
    <td><a href="https://leetcode.com/problems/continuous-subarray-sum/">Continuous Subarray Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/523.%20Continuous%20Subarray%20Sum/ContinuousSubarraySum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">560</td>
    <td><a href="https://leetcode.com/problems/subarray-sum-equals-k/">Subarray Sum Equals K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/560.%20Subarray%20Sum%20Equals%20K/SubarraySumEqualsK.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">974</td>
    <td><a href="https://leetcode.com/problems/subarray-sums-divisible-by-k/">Subarray Sums Divisible by K</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/974.%20Subarray%20Sums%20Divisible%20by%20K/SubarraySumsDivisibleByK_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1480</td>
    <td><a href="https://leetcode.com/problems/running-sum-of-1d-array/">Running Sum of 1D Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1480.%20Running%20Sum%20of%201D%20Array/RunningSumOf1DArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1732</td>
    <td><a href="https://leetcode.com/problems/find-the-highest-altitude/">Find the Highest Altitude</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1732.%20Find%20the%20Highest%20Altitude/FindTheHighestAltitude.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2389</td>
    <td><a href="https://leetcode.com/problems/longest-subsequence-with-limited-sum/">Longest Subsequence With Limited Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2389.%20Longest%20Subsequence%20With%20Limited%20Sum/LongestSubsequenceWithLimitedSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#prefix-sum">Prefix Sum</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2438</td>
    <td><a href="https://leetcode.com/problems/range-product-queries-of-powers/">Range Product Queries of Powers</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2438.%20Range%20Product%20Queries%20of%20Powers/RangeProductQueriesOfPowers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#prefix-sum">Prefix Sum</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="queue">Queue</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">225</td>
    <td><a href="https://leetcode.com/problems/implement-stack-using-queues/">Implement Stack using Queues</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/225.%20Implement%20Stack%20using%20Queues/ImplementStackUsingQueues.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">232</td>
    <td><a href="https://leetcode.com/problems/implement-queue-using-stacks/">Implement Queue using Stacks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/232.%20Implement%20Queue%20using%20Stacks/ImplementQueueUsingStacks.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="recursion">Recursion</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">24</td>
    <td><a href="https://leetcode.com/problems/swap-nodes-in-pairs/">Swap Nodes in Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/24.%20Swap%20Nodes%20in%20Pairs/SwapNodesInPairs.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/24.%20Swap%20Nodes%20in%20Pairs/SwapNodesInPairs.java"><em>Iteration</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">206</td>
    <td><a href="https://leetcode.com/problems/reverse-linked-list/">Reverse Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList_Recursive.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList.java"><em>Array List</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/206.%20Reverse%20Linked%20List/ReverseLinkedList.java">Reverse Nodes Iteratively</a>
    </td>
  </tr>
  <tr>
    <td align="center">509</td>
    <td><a href="https://leetcode.com/problems/fibonacci-number/">Fibonacci Number</a></td>
    <td align="center">Java with Dynamic Programming -
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Iterative.java">Tabulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/509.%20Fibonacci%20Number/FibonacciNumber_Recursive.java">Memoization</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#memoization">Memoization</a>,
      <a href="#recursion">Recursion</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="simulation">Simulation</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">412</td>
    <td><a href="https://leetcode.com/problems/fizz-buzz/">Fizz Buzz</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/412.%20Fizz%20Buzz/FizzBuzz.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">985</td>
    <td><a href="https://leetcode.com/problems/sum-of-even-numbers-after-queries/">Sum of Even Numbers After Queries</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/985.%20Sum%20of%20Even%20Numbers%20After%20Queries/SumOfEvenNumbersAfterQueries.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1103</td>
    <td><a href="https://leetcode.com/problems/distribute-candies-to-people/">Distribute Candies to People</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1103.%20Distribute%20Candies%20to%20People/DistributeCandiesToPeople.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1603</td>
    <td><a href="https://leetcode.com/problems/design-parking-system/">Design Parking System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1603.%20Design%20Parking%20System/ParkingSystem.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#design">Design</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1680</td>
    <td><a href="https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers/">Concatenation of Consecutive Binary Numbers</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_BitManipulation.java">Bit Manipulation</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1680.%20Concatenation%20of%20Consecutive%20Binary%20Numbers/ConcatenationOfConsecutiveBinaryNumbers_Math.java">Math</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1920</td>
    <td><a href="https://leetcode.com/problems/build-array-from-permutation/">Build Array from Permutation</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1920.%20Build%20Array%20from%20Permutation/BuildArrayFromPermutation.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2028</td>
    <td><a href="https://leetcode.com/problems/find-missing-observations/">Find Missing Observations</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2028.%20Find%20Missing%20Observations/FindMissingObservations.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2169</td>
    <td><a href="https://leetcode.com/problems/count-operations-to-obtain-zero/">Count Operations to Obtain Zero</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2169.%20Count%20Operations%20to%20Obtain%20Zero/CountOperationsToObtainZero.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2352</td>
    <td><a href="https://leetcode.com/problems/equal-row-and-column-pairs/">Equal Row and Column Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2352.%20Equal%20Row%20and%20Column%20Pairs/EqualRowAndColumnPairs.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#simulation">Simulation</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="sliding-window">Sliding Window</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">3</td>
    <td><a href="https://leetcode.com/problems/longest-substring-without-repeating-characters/">Longest Substring Without Repeating Characters</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters_HashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters.java">without</a> Hash Table
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">219</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-ii/">Contains Duplicate II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_SlidingWindow.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/219.%20Contains%20Duplicate%20II/ContainsDuplicateII_HashMap.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">220</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-iii/">Contains Duplicate III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_HashMap_BucketSort.java">Sliding Window & Bucket Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_TreeSet_OrderedSet.java">Sliding Window & Ordered Set</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bucket-sort">Bucket Sort</a>,
      <a href="#ordered-set">Ordered Set</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">438</td>
    <td><a href="https://leetcode.com/problems/find-all-anagrams-in-a-string/">Find All Anagrams in a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/438.%20Find%20All%20Anagrams%20in%20a%20String/FindAllAnagramsInAString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">567</td>
    <td><a href="https://leetcode.com/problems/permutation-in-string/">Permutation in String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/567.%20Permutation%20in%20String/PermutationInString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">713</td>
    <td><a href="https://leetcode.com/problems/subarray-product-less-than-k/">Subarray Product Less Than K</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/713.%20Subarray%20Product%20Less%20Than%20K/SubarrayProductLessThanK.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">904</td>
    <td><a href="https://leetcode.com/problems/fruit-into-baskets/">Fruit Into Baskets</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/904.%20Fruit%20Into%20Baskets/FruitIntoBaskets.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="sorting">Sorting</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">15</td>
    <td><a href="https://leetcode.com/problems/3sum/">3Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/15.%203Sum/ThreeSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">16</td>
    <td><a href="https://leetcode.com/problems/3sum-closest/">3Sum Closest</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/16.%203Sum%20Closest/ThreeSumClosest.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">49</td>
    <td><a href="https://leetcode.com/problems/group-anagrams/">Group Anagrams</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/49.%20Group%20Anagrams/GroupAnagrams.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">88</td>
    <td><a href="https://leetcode.com/problems/merge-sorted-array/">Merge Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">169</td>
    <td><a href="https://leetcode.com/problems/majority-element/">Majority Element</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#divide-and-conquer">Divide and Conquer</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_DivideAndConquer_Counting.java"><em>Counting & Divide and Conquer</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/169.%20Majority%20Element/MajorityElement_HashTable_Counting.java"><em>Counting & Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">217</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate/">Contains Duplicate</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashMap.java"><em>Hash Map</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/217.%20Contains%20Duplicate/ContainsDuplicate_HashSet.java"><em>Hash Set</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">220</td>
    <td><a href="https://leetcode.com/problems/contains-duplicate-iii/">Contains Duplicate III</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bucket-sort">Bucket Sort</a>,
      <a href="#ordered-set">Ordered Set</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_HashMap_BucketSort.java"><em>Sliding Window & Bucket Sort</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/220.%20Contains%20Duplicate%20III/ContainsDuplicateIII_SlidingWindow_TreeSet_OrderedSet.java"><em>Sliding Window & Ordered Set</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">229</td>
    <td><a href="https://leetcode.com/problems/majority-element-ii/">Majority Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_BoyerMooreVotingAlgorithm.java"><em>Boyer-Moore Majority Voting Algorithm</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/229.%20Majority%20Element%20II/MajorityElementII_HashTable_Counting.java"><em>Counting & Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">274</td>
    <td><a href="https://leetcode.com/problems/h-index/">H-Index</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_CountingSort.java">Counting Sort</a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/274.%20H-Index/HIndex_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">295</td>
    <td><a href="https://leetcode.com/problems/find-median-from-data-stream/">Find Median from Data Stream</a></td>
    <td align="center"><a>Java with </a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/295.%20Find%20Median%20from%20Data%20Stream/MedianFinder_PriorityQueue.java">Heap (Priority Queue)</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#data-stream">Data Stream</a>,
      <a href="#design">Design</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Use of Sorting & Two Pointers resulted in TLE (Time Limit Exceed) for large datasets.</td>
  </tr>
  <tr>
    <td align="center">414</td>
    <td><a href="https://leetcode.com/problems/third-maximum-number/">Third Maximum Number</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber_Sorting.java"><em>without Sorting</em></a> or Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/414.%20Third%20Maximum%20Number/ThirdMaximumNumber_PriorityQueue_HashSet.java"><em>Hash Table & Priority Queue</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">561</td>
    <td><a href="https://leetcode.com/problems/array-partition/">Array Partition</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_CountingSort_Greedy.java">Greedy & Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/561.%20Array%20Partition/ArrayPartition_Sorting_Greedy.java">Greedy & Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">645</td>
    <td><a href="https://leetcode.com/problems/set-mismatch/">Set Mismatch</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_BitManipulation.java"><em>Bit Manipulation</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/645.%20Set%20Mismatch/SetMismatch_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">905</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity/">Sort Array By Parity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/905.%20Sort%20Array%20By%20Parity/SortArrayByParity.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">922</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity-ii/">Sort Array By Parity II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/922.%20Sort%20Array%20By%20Parity%20II/SortArrayByParityII.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">923</td>
    <td><a href="https://leetcode.com/problems/3sum-with-multiplicity/">3Sum With Multiplicity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Sorting_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Counting.java"><em>Counting</em></a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">948</td>
    <td><a href="https://leetcode.com/problems/bag-of-tokens/">Bag of Tokens</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/948.%20Bag%20of%20Tokens/BagOfTokens.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">976</td>
    <td><a href="https://leetcode.com/problems/largest-perimeter-triangle/">Largest Perimeter Triangle</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/976.%20Largest%20Perimeter%20Triangle/LargestPerimeterTriangle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">977</td>
    <td><a href="https://leetcode.com/problems/squares-of-a-sorted-array/">Squares of a Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1051</td>
    <td><a href="https://leetcode.com/problems/height-checker/">Height Checker</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_CountingSort.java">Counting Sort</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1051.%20Height%20Checker/HeightChecker_Sorting.java">Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1122</td>
    <td><a href="https://leetcode.com/problems/relative-sort-array/">Relative Sort Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_CountingSort_Sorting.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting-sort">Counting Sort</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1122.%20Relative%20Sort%20Array/RelativeSortArray_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1337</td>
    <td><a href="https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/">The K Weakest Rows in a Matrix</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_Sorting.java">Sorting & Binary Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix.java"><em>Linear Search</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch.java">Binary Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1337.%20The%20K%20Weakest%20Rows%20in%20a%20Matrix/TheKWeakestRowsInAMatrix_BinarySearch_PriorityQueue.java"><em>Heap (Priority Queue) & Binary Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1346</td>
    <td><a href="https://leetcode.com/problems/check-if-n-and-its-double-exist/">Check If N and Its Double Exist</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_Sorting_BinarySearch.java">Binary Search & Sorting</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_HashTable.java"><em>Hash Table</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1636</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-increasing-frequency/">Sort Array by Increasing Frequency</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1636.%20Sort%20Array%20by%20Increasing%20Frequency/SortArrayByIncreasingFrequency.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1657</td>
    <td><a href="https://leetcode.com/problems/determine-if-two-strings-are-close/">Determine if Two Strings Are Close</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting.java">Sorting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting_HashTable.java">Hash Table & Sorting</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1679</td>
    <td><a href="https://leetcode.com/problems/max-number-of-k-sum-pairs/">Max Number of K-Sum Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_Sorting_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1833</td>
    <td><a href="https://leetcode.com/problems/maximum-ice-cream-bars/">Maximum Ice Cream Bars</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1833.%20Maximum%20Ice%20Cream%20Bars/MaximumIceCreamBars.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1834</td>
    <td><a href="https://leetcode.com/problems/single-threaded-cpu/">Single-Threaded CPU</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1834.%20Single-Threaded%20CPU/SingleThreadedCPU.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2007</td>
    <td><a href="https://leetcode.com/problems/find-original-array-from-doubled-array/">Find Original Array From Doubled Array</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_HashMap_Sorting.java">Hash Table</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Queue_Sorting.java">Queue</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2007.%20Find%20Original%20Array%20From%20Doubled%20Array/FindOriginalArrayFromDoubledArray_Counting.java"><em>Counting Array</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2136</td>
    <td><a href="https://leetcode.com/problems/earliest-possible-day-of-full-bloom/">Earliest Possible Day of Full Bloom</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2136.%20Earliest%20Possible%20Day%20of%20Full%20Bloom/EarliestPossibleDayOfFullBloom.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2279</td>
    <td><a href="https://leetcode.com/problems/maximum-bags-with-full-capacity-of-rocks/">Maximum Bags With Full Capacity of Rocks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2279.%20Maximum%20Bags%20With%20Full%20Capacity%20of%20Rocks/MaximumBagsWithFullCapacityOfRocks.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2389</td>
    <td><a href="https://leetcode.com/problems/longest-subsequence-with-limited-sum/">Longest Subsequence With Limited Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2389.%20Longest%20Subsequence%20With%20Limited%20Sum/LongestSubsequenceWithLimitedSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#prefix-sum">Prefix Sum</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="stack">Stack</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">94</td>
    <td><a href="https://leetcode.com/problems/binary-tree-inorder-traversal/">Binary Tree Inorder Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Iterative.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">114</td>
    <td><a href="https://leetcode.com/problems/flatten-binary-tree-to-linked-list/">Flatten Binary Tree to Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Iterative.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">144</td>
    <td><a href="https://leetcode.com/problems/binary-tree-preorder-traversal/">Binary Tree Preorder Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Iterative.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">145</td>
    <td><a href="https://leetcode.com/problems/binary-tree-postorder-traversal/">Binary Tree Postorder Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Iterative.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">225</td>
    <td><a href="https://leetcode.com/problems/implement-stack-using-queues/">Implement Stack using Queues</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/225.%20Implement%20Stack%20using%20Queues/ImplementStackUsingQueues.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">232</td>
    <td><a href="https://leetcode.com/problems/implement-queue-using-stacks/">Implement Queue using Stacks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/232.%20Implement%20Queue%20using%20Stacks/ImplementQueueUsingStacks.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#design">Design</a>,
      <a href="#queue">Queue</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">496</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-i/">Next Greater Element I</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/496.%20Next%20Greater%20Element%20I/NextGreaterElementI_HashTable_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">503</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-ii/">Next Greater Element II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/503.%20Next%20Greater%20Element%20II/NextGreaterElementII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1019</td>
    <td><a href="https://leetcode.com/problems/next-greater-node-in-linked-list/">Next Greater Node In Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1019.%20Next%20Greater%20Node%20In%20Linked%20List/NextGreaterNodeInLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1047</td>
    <td><a href="https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/">Remove All Adjacent Duplicates In String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1047.%20Remove%20All%20Adjacent%20Duplicates%20In%20String/RemoveAllAdjacentDuplicatesInString_Stack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#stack">Stack</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1047.%20Remove%20All%20Adjacent%20Duplicates%20In%20String/RemoveAllAdjacentDuplicatesInString_StringBuilder.java"><em>StringBuilder only</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1544</td>
    <td><a href="https://leetcode.com/problems/make-the-string-great/">Make The String Great</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1544.%20Make%20The%20String%20Great/MakeTheStringGreat_Stack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#stack">Stack</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2130</td>
    <td><a href="https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/">Maximum Twin Sum of a Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers_Stack.java">Two Pointers & Stack</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers.java"><em>only Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2454</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iv/">Next Greater Element IV</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2454.%20Next%20Greater%20Element%20IV/NextGreaterElementIV_MonotonicStack.java">Java</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#monotonic-stack">Monotonic Stack</a>,
      <a href="#stack">Stack</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="string">String</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">3</td>
    <td><a href="https://leetcode.com/problems/longest-substring-without-repeating-characters/">Longest Substring Without Repeating Characters</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters_HashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/3.%20Longest%20Substring%20Without%20Repeating%20Characters/LongestSubstringWithoutRepeatingCharacters.java">without</a> Hash Table
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">5</td>
    <td><a href="https://leetcode.com/problems/longest-palindromic-substring/">Longest Palindromic Substring</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_DynamicProgramming.java">Dynamic Programming</a>, Two Pointers with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_TwoPointers1.java">Approach 1</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/5.%20Longest%20Palindromic%20Substring/LongestPalindromicSubstring_TwoPointers2.java">Approach 2</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">6</td>
    <td><a href="https://leetcode.com/problems/zigzag-conversion/">Zigzag Conversion</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/6.%20Zigzag%20Conversion/ZigzagConversion.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">12</td>
    <td><a href="https://leetcode.com/problems/integer-to-roman/">Integer to Roman</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_HashTable.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/12.%20Integer%20to%20Roman/IntegerToRoman_WithoutHashTable.java">without Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">13</td>
    <td><a href="https://leetcode.com/problems/roman-to-integer/">Roman to Integer</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_HashMap.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/13.%20Roman%20to%20Integer/RomanToInteger_WithoutHashMap.java">without Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">38</td>
    <td><a href="https://leetcode.com/problems/count-and-say/">Count and Say</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/38.%20Count%20and%20Say/CountAndSay_Iterative.java">Iterative </a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/38.%20Count%20and%20Say/CountAndSay_Recursive.java">Recursive</a> Algorithms
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">49</td>
    <td><a href="https://leetcode.com/problems/group-anagrams/">Group Anagrams</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/49.%20Group%20Anagrams/GroupAnagrams.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">151</td>
    <td><a href="https://leetcode.com/problems/reverse-words-in-a-string/">Reverse Words in a String</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_StringBuilder.java">StringBuilder</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_Collections.java">Collections</a> Implementations
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_TwoPointers.java"><em>Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">205</td>
    <td><a href="https://leetcode.com/problems/isomorphic-strings/">Isomorphic Strings</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/205.%20Isomorphic%20Strings/IsomorphicStrings.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">257</td>
    <td><a href="https://leetcode.com/problems/binary-tree-paths/">Binary Tree Paths</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">290</td>
    <td><a href="https://leetcode.com/problems/word-pattern/">Word Pattern</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/290.%20Word%20Pattern/WordPattern.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">344</td>
    <td><a href="https://leetcode.com/problems/reverse-string/">Reverse String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/344.%20Reverse%20String/ReverseString_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">345</td>
    <td><a href="https://leetcode.com/problems/reverse-vowels-of-a-string/">Reverse Vowels of a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/345.%20Reverse%20Vowels%20of%20a%20String/ReverseVowelsOfAString_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">368</td>
    <td><a href="https://leetcode.com/problems/largest-divisible-subset/">Largest Divisible Subset</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/368.%20Largest%20Divisible%20Subset/LargestDivisibleSubset.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#math">Math</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">383</td>
    <td><a href="https://leetcode.com/problems/ransom-note/">Ransom Note</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_Counting.java">Counting Array</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/383.%20Ransom%20Note/RansomNote_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">412</td>
    <td><a href="https://leetcode.com/problems/fizz-buzz/">Fizz Buzz</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/412.%20Fizz%20Buzz/FizzBuzz.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#simulation">Simulation</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">438</td>
    <td><a href="https://leetcode.com/problems/find-all-anagrams-in-a-string/">Find All Anagrams in a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/438.%20Find%20All%20Anagrams%20in%20a%20String/FindAllAnagramsInAString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">520</td>
    <td><a href="https://leetcode.com/problems/detect-capital/">Detect Capital</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/520.%20Detect%20Capital/DetectCapital.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">541</td>
    <td><a href="https://leetcode.com/problems/reverse-string-ii/">Reverse String II</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/541.%20Reverse%20String%20II/ReverseStringII_StringBuilder.java">StringBuilder</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/541.%20Reverse%20String%20II/ReverseStringII_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">556</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iii/">Next Greater Element III</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/556.%20Next%20Greater%20Element%20III/NextGreaterElementIII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">557</td>
    <td><a href="https://leetcode.com/problems/reverse-words-in-a-string-iii/">Reverse Words in a String III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/557.%20Reverse%20Words%20in%20a%20String%20III/ReverseWordsInAStringIII_StringBuilder.java">String Builder</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/557.%20Reverse%20Words%20in%20a%20String%20III/ReverseWordsInAStringIII_TwoPointers.java">Two Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">567</td>
    <td><a href="https://leetcode.com/problems/permutation-in-string/">Permutation in String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/567.%20Permutation%20in%20String/PermutationInString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">609</td>
    <td><a href="https://leetcode.com/problems/find-duplicate-file-in-system/">Find Duplicate File in System</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/609.%20Find%20Duplicate%20File%20in%20System/FindDuplicateFileInSystem_HashMap.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">929</td>
    <td><a href="https://leetcode.com/problems/unique-email-addresses/">Unique Email Addresses</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/929.%20Unique%20Email%20Addresses/UniqueEmailAddresses_HashSet.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">944</td>
    <td><a href="https://leetcode.com/problems/delete-columns-to-make-sorted/">Delete Columns to Make Sorted</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/944.%20Delete%20Columns%20to%20Make%20Sorted/DeleteColumnsToMakeSorted.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">953</td>
    <td><a href="https://leetcode.com/problems/verifying-an-alien-dictionary/">Verifying an Alien Dictionary</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/953.%20Verifying%20an%20Alien%20Dictionary/VerifyingAnAlienDictionary.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">988</td>
    <td><a href="https://leetcode.com/problems/smallest-string-starting-from-leaf/">Smallest String Starting From Leaf</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1047</td>
    <td><a href="https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/">Remove All Adjacent Duplicates In String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1047.%20Remove%20All%20Adjacent%20Duplicates%20In%20String/RemoveAllAdjacentDuplicatesInString_StringBuilder.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#stack">Stack</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1047.%20Remove%20All%20Adjacent%20Duplicates%20In%20String/RemoveAllAdjacentDuplicatesInString_Stack.java"><em>Stack</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1061</td>
    <td><a href="https://leetcode.com/problems/lexicographically-smallest-equivalent-string/">Lexicographically Smallest Equivalent String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1061.%20Lexicographically%20Smallest%20Equivalent%20String/LexicographicallySmallestEquivalentString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1071</td>
    <td><a href="https://leetcode.com/problems/greatest-common-divisor-of-strings/">Greatest Common Divisor of Strings</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1071.%20Greatest%20Common%20Divisor%20of%20Strings/GreatestCommonDivisorOfStrings.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1154</td>
    <td><a href="https://leetcode.com/problems/day-of-the-year/">Day of the Year</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1154.%20Day%20of%20the%20Year/DayOfTheYear.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1239</td>
    <td><a href="https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters/">Maximum Length of a Concatenated String with Unique Characters</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_Backtracking.java">Backtracking</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1239.%20Maximum%20Length%20of%20a%20Concatenated%20String%20with%20Unique%20Characters/MaximumLengthOfAConcatenatedStringWithUniqueCharacters_BitManipulation.java">Bit Manipulation</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#backtracking">Backtracking</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1328</td>
    <td><a href="https://leetcode.com/problems/break-a-palindrome/">Break a Palindrome</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1328.%20Break%20a%20Palindrome/BreakAPalindrome.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1446</td>
    <td><a href="https://leetcode.com/problems/consecutive-characters/">Consecutive Characters</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1446.%20Consecutive%20Characters/ConsecutiveCharacters.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1544</td>
    <td><a href="https://leetcode.com/problems/make-the-string-great/">Make The String Great</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1544.%20Make%20The%20String%20Great/MakeTheStringGreat_Stack.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#stack">Stack</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1578</td>
    <td><a href="https://leetcode.com/problems/minimum-time-to-make-rope-colorful/">Minimum Time to Make Rope Colorful</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_DynamicProgramming.java">Dynamic Programming</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1578.%20Minimum%20Time%20to%20Make%20Rope%20Colorful/MinimumTimeToMakeRopeColorful_Greedy.java">Greedy</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#dynamic-programming">Dynamic Programming</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1592</td>
    <td><a href="https://leetcode.com/problems/rearrange-spaces-between-words/">Rearrange Spaces Between Words</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1592.%20Rearrange%20Spaces%20Between%20Words/RearrangeSpacesBetweenWords.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1657</td>
    <td><a href="https://leetcode.com/problems/determine-if-two-strings-are-close/">Determine if Two Strings Are Close</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting.java">Sorting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1657.%20Determine%20if%20Two%20Strings%20Are%20Close/DetermineIfTwoStringsAreClose_Sorting_HashTable.java">Hash Table & Sorting</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1662</td>
    <td><a href="https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/">Check If Two String Arrays are Equivalent</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1662.%20Check%20If%20Two%20String%20Arrays%20are%20Equivalent/CheckIfTwoStringArraysAreEquivalent_Pointers.java">with</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1662.%20Check%20If%20Two%20String%20Arrays%20are%20Equivalent/CheckIfTwoStringArraysAreEquivalent_String.java">without Pointers</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1704</td>
    <td><a href="https://leetcode.com/problems/determine-if-string-halves-are-alike/">Determine if String Halves Are Alike</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1704.%20Determine%20if%20String%20Halves%20Are%20Alike/DetermineIfStringHalvesAreAlike.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1832</td>
    <td><a href="https://leetcode.com/problems/check-if-the-sentence-is-pangram/">Check if the Sentence is Pangram</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_BitManipulation.java"><em>Bit Manipulation</em></a> ,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_Counting.java"><em>Counting</em></a> and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1832.%20Check%20if%20the%20Sentence%20Is%20Pangram/CheckIfTheSentenceIsPangram_HashSet.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1869</td>
    <td><a href="https://leetcode.com/problems/longer-contiguous-segments-of-ones-than-zeros/">Longer Contiguous Segments of Ones than Zeros</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1869.%20Longer%20Contiguous%20Segments%20of%20Ones%20than%20Zeros/LongerContiguousSegmentsOfOnesThanZeros.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1935</td>
    <td><a href="https://leetcode.com/problems/maximum-number-of-words-you-can-type/">Maximum Number of Words You Can Type</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1935.%20Maximum%20Number%20of%20Words%20You%20Can%20Type/MaximumNumberOfWordsYouCanType.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2023</td>
    <td><a href="https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target/">Number of Pairs of Strings With Concatenation Equal to Target</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2023.%20Number%20of%20Pairs%20of%20Strings%20With%20Concatenation%20Equal%20to%20Target/NumberOfPairsOfStringsWithConcatenationEqualToTarget_HashTable.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2129</td>
    <td><a href="https://leetcode.com/problems/capitalize-the-title/">Capitalize the Title</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2129.%20Capitalize%20the%20Title/CapitalizeTheTitle.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2131</td>
    <td><a href="https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/">Longest Palindrome by Concatenating Two Letter Words</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2131.%20Longest%20Palindrome%20by%20Concatenating%20Two%20Letter%20Words/LongestPalindromeByConcatenatingTwoLetterWords_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2315</td>
    <td><a href="https://leetcode.com/problems/count-asterisks/">Count Asterisks</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2315.%20Count%20Asterisks/CountAsterisks.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2351</td>
    <td><a href="https://leetcode.com/problems/first-letter-to-appear-twice/">First Letter to Appear Twice</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_Counting.java">Counting</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2351.%20First%20Letter%20to%20Appear%20Twice/FirstLetterToAppearTwice_HashTable.java">Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2399</td>
    <td><a href="https://leetcode.com/problems/check-distances-between-same-letters/">Check Distances Between Same Letters</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2399.%20Check%20Distances%20Between%20Same%20Letters/CheckDistancesBetweenSameLetters_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2437</td>
    <td><a href="https://leetcode.com/problems/number-of-valid-clock-times/">Number of Valid Clock Times</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2437.%20Number%20of%20Valid%20Clock%20Times/NumberOfValidClockTimes.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#enumeration">Enumeration</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2451</td>
    <td><a href="https://leetcode.com/problems/odd-string-difference/">Odd String Difference</a></td>
    <td align="center">Java
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference.java">without</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2451.%20Odd%20String%20Difference/OddStringDifference_HashTable.java">with Hash Table</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#math">Math</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2452</td>
    <td><a href="https://leetcode.com/problems/words-within-two-edits-of-dictionary/">Words Within Two Edits of Dictionary</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2452.%20Words%20Within%20Two%20Edits%20of%20Dictionary/WordsWithinTwoEditsOfDictionary.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#string">String</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="tree">Tree</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">94</td>
    <td><a href="https://leetcode.com/problems/binary-tree-inorder-traversal/">Binary Tree Inorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/94.%20Binary%20Tree%20Inorder%20Traversal/BinaryTreeInorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">98</td>
    <td><a href="https://leetcode.com/problems/validate-binary-search-tree/">Validate Binary Search Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/98.%20Validate%20Binary%20Search%20Tree/ValidateBinarySearchTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">100</td>
    <td><a href="https://leetcode.com/problems/same-tree/">Same Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_BFS.java">Breadth-First Search</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/100.%20Same%20Tree/SameTree_DFS.java">Depth-First Search</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">102</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal/">Binary Tree Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/102.%20Binary%20Tree%20Level%20Order%20Traversal/BinaryTreeLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">103</td>
    <td><a href="https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/">Binary Tree Zigzag Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/103.%20Binary%20Tree%20Zigzag%20Level%20Order%20Traversal/BinaryTreeZigzagLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">104</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/104.%20Maximum%20Depth%20of%20Binary%20Tree/MaximumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">107</td>
    <td><a href="https://leetcode.com/problems/binary-tree-level-order-traversal-ii/">Binary Tree Level Order Traversal II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/107.%20Binary%20Tree%20Level%20Order%20Traversal%20II/BinaryTreeLevelOrderTraversalII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">110</td>
    <td><a href="https://leetcode.com/problems/balanced-binary-tree/">Balanced Binary Tree</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/110.%20Balanced%20Binary%20Tree/BalancedBinaryTree.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">111</td>
    <td><a href="https://leetcode.com/problems/minimum-depth-of-binary-tree/">Minimum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/111.%20Minimum%20Depth%20of%20Binary%20Tree/MinimumDepthOfBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">112</td>
    <td><a href="https://leetcode.com/problems/path-sum/">Path Sum</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/112.%20Path%20Sum/PathSum_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">113</td>
    <td><a href="https://leetcode.com/problems/path-sum-ii/">Path Sum II</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/113.%20Path%20Sum%20II/PathSumII_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">114</td>
    <td><a href="https://leetcode.com/problems/flatten-binary-tree-to-linked-list/">Flatten Binary Tree to Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List/FlattenBinaryTreeToLinkedList_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">129</td>
    <td><a href="https://leetcode.com/problems/sum-root-to-leaf-numbers/">Sum Root to Leaf Numbers</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/129.%20Sum%20Root%20to%20Leaf%20Numbers/SumRootToLeafNumbers_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">144</td>
    <td><a href="https://leetcode.com/problems/binary-tree-preorder-traversal/">Binary Tree Preorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/144.%20Binary%20Tree%20Preorder%20Traversal/BinaryTreePreorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">145</td>
    <td><a href="https://leetcode.com/problems/binary-tree-postorder-traversal/">Binary Tree Postorder Traversal</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/145.%20Binary%20Tree%20Postorder%20Traversal/BinaryTreePostorderTraversal_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#stack">Stack</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">222</td>
    <td><a href="https://leetcode.com/problems/count-complete-tree-nodes/">Count Complete Tree Nodes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/222.%20Count%20Complete%20Tree%20Nodes/CountCompleteTreeNodes.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-search">Binary Search</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">226</td>
    <td><a href="https://leetcode.com/problems/invert-binary-tree/">Invert Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/226.%20Invert%20Binary%20Tree/InvertBinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">257</td>
    <td><a href="https://leetcode.com/problems/binary-tree-paths/">Binary Tree Paths</a></td>
    <td align="center">Java with Backtracking and
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Iterative_Backtracking.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/257.%20Binary%20Tree%20Paths/BinaryTreePaths_DFS_Recursive_Backtracking.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#backtracking">Backtracking</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">404</td>
    <td><a href="https://leetcode.com/problems/sum-of-left-leaves/">Sum of Left Leaves</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/404.%20Sum%20of%20Left%20Leaves/SumOfLeftLeaves_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">429</td>
    <td><a href="https://leetcode.com/problems/n-ary-tree-level-order-traversal/">N-ary Tree Level Order Traversal</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/429.%20N-ary%20Tree%20Level%20Order%20Traversal/NAryTreeLevelOrderTraversal.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">437</td>
    <td><a href="https://leetcode.com/problems/path-sum-iii/">Path Sum III</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/437.%20Path%20Sum%20III/PathSumIII_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">559</td>
    <td><a href="https://leetcode.com/problems/maximum-depth-of-binary-tree/">Maximum Depth of Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/559.%20Maximum%20Depth%20of%20N-ary%20Tree/MaximumDepthOfNAryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java">Breadth-First Search (with Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java">Breadth-First Search (without Hash Table)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java">Depth-First Search (Iterative)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java">Depth-First Search (Recursive)</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java">Two Pointers (with Iterative Inorder Traversal)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java">Two Pointers (with Recursive Inorder Traversal)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">783</td>
    <td><a href="https://leetcode.com/problems/minimum-distance-between-bst-nodes/">Minimum Distance Between BST Nodes</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/783.%20Minimum%20Distance%20Between%20BST%20Nodes/MinimumDistanceBetweenBSTNodes_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">988</td>
    <td><a href="https://leetcode.com/problems/smallest-string-starting-from-leaf/">Smallest String Starting From Leaf</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/988.%20Smallest%20String%20Starting%20From%20Leaf/SmallestStringStartingFromLeaf_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#string">String</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1026</td>
    <td><a href="https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/">Maximum Difference Between Node and Ancestor</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1026.%20Maximum%20Difference%20Between%20Node%20and%20Ancestor/MaximumDifferenceBetweenNodeAndAncestor_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1457</td>
    <td><a href="https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/">Pseudo-Palindromic Paths in a Binary Tree</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_BFS.java">Breadth-First Search</a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Iterative.java">Depth-First Search (Iterative)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1457.%20Pseudo-Palindromic%20Paths%20in%20a%20Binary%20Tree/PseudoPalindromicPathsInABinaryTree_DFS_Recursive.java">Depth-First Search (Recursive)</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#bit-manipulation">Bit Manipulation</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#tree">Tree</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="two-pointers">Two Pointers</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">15</td>
    <td><a href="https://leetcode.com/problems/3sum/">3Sum</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/15.%203Sum/ThreeSum.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">16</td>
    <td><a href="https://leetcode.com/problems/3sum-closest/">3Sum Closest</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/16.%203Sum%20Closest/ThreeSumClosest.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">19</td>
    <td><a href="https://leetcode.com/problems/remove-nth-node-from-end-of-list/">Remove Nth Node From End of List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/19.%20Remove%20Nth%20Node%20From%20End%20of%20List/RemoveNthNodeFromEndOfList_OnePass.java">One Pass</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/19.%20Remove%20Nth%20Node%20From%20End%20of%20List/RemoveNthNodeFromEndOfList_TwoPasses.java">Two Passes</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">26</td>
    <td><a href="https://leetcode.com/problems/remove-duplicates-from-sorted-array/">Remove Duplicates from Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/26.%20Remove%20Duplicates%20from%20Sorted%20Array/RemoveDuplicatesFromSortedArray.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">27</td>
    <td><a href="https://leetcode.com/problems/remove-element/">Remove Element</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/27.%20Remove%20Element/RemoveElement.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">80</td>
    <td><a href="https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/">Remove Duplicates from Sorted Array II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/80.%20Remove%20Duplicates%20from%20Sorted%20Array%20II/RemoveDuplicatesFromSortedArrayII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">88</td>
    <td><a href="https://leetcode.com/problems/merge-sorted-array/">Merge Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/88.%20Merge%20Sorted%20Array/MergeSortedArray_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">151</td>
    <td><a href="https://leetcode.com/problems/reverse-words-in-a-string/">Reverse Words in a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_Collections.java"><em>Collections</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/151.%20Reverse%20Words%20in%20a%20String/ReverseWordsInAString_StringBuilder.java"><em>StringBuilder</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">167</td>
    <td><a href="https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/">Two Sum II - Input Array is Sorted</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/167.%20Two%20Sum%20II%20-%20Input%20Array%20is%20Sorted/TwoSumII_InputArrayIsSorted_BinarySearch.java"><em>Binary Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">283</td>
    <td><a href="https://leetcode.com/problems/move-zeroes/">Move Zeroes</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/283.%20Move%20Zeroes/MoveZeroes.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">295</td>
    <td><a href="https://leetcode.com/problems/find-median-from-data-stream/">Find Median from Data Stream</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/295.%20Find%20Median%20from%20Data%20Stream/MedianFinder_PriorityQueue.java">Heap (Priority Queue)</a>
    </td>
    <td align="center">$\text{\color{Red}Hard}$</td>
    <td align="center">
      <a href="#data-stream">Data Stream</a>,
      <a href="#design">Design</a>,
      <a href="#heap-priority-queue">Heap (Priority Queue)</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Use of Sorting & Two Pointers resulted in TLE (Time Limit Exceed) for large datasets.</td>
  </tr>
  <tr>
    <td align="center">344</td>
    <td><a href="https://leetcode.com/problems/reverse-string/">Reverse String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/344.%20Reverse%20String/ReverseString_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">345</td>
    <td><a href="https://leetcode.com/problems/reverse-vowels-of-a-string/">Reverse Vowels of a String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/345.%20Reverse%20Vowels%20of%20a%20String/ReverseVowelsOfAString_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">541</td>
    <td><a href="https://leetcode.com/problems/reverse-string-ii/">Reverse String II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/541.%20Reverse%20String%20II/ReverseStringII_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/541.%20Reverse%20String%20II/ReverseStringII_StringBuilder.java"><em>StringBuilder</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">556</td>
    <td><a href="https://leetcode.com/problems/next-greater-element-iii/">Next Greater Element III</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/556.%20Next%20Greater%20Element%20III/NextGreaterElementIII.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#math">Math</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">557</td>
    <td><a href="https://leetcode.com/problems/reverse-words-in-a-string-iii/">Reverse Words in a String III</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/557.%20Reverse%20Words%20in%20a%20String%20III/ReverseWordsInAStringIII_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/557.%20Reverse%20Words%20in%20a%20String%20III/ReverseWordsInAStringIII_StringBuilder.java"><em>String Builder</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">567</td>
    <td><a href="https://leetcode.com/problems/permutation-in-string/">Permutation in String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/567.%20Permutation%20in%20String/PermutationInString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#hash-table">Hash Table</a>,
      <a href="#sliding-window">Sliding Window</a>,
      <a href="#string">String</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">653</td>
    <td><a href="https://leetcode.com/problems/two-sum-iv-input-is-a-bst/">Two Sum IV - Input is a BST</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative_TwoPointers.java">Two Pointers (with Iterative Inorder Traversal)</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive_TwoPointers.java">Two Pointers (with Recursive Inorder Traversal)</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#binary-search-tree">Binary Search Tree</a>,
      <a href="#binary-tree">Binary Tree</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#tree">Tree</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithHashTable.java"><em>Breadth-First Search (with Hash Table)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_BFS_WithoutHashTable.java"><em>Breadth-First Search (without Hash Table)</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST/TwoSumIV_InputIsABST_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">876</td>
    <td><a href="https://leetcode.com/problems/middle-of-the-linked-list/">Middle of the Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/876.%20Middle%20of%20the%20Linked%20List/MiddleOfTheLinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">905</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity/">Sort Array By Parity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/905.%20Sort%20Array%20By%20Parity/SortArrayByParity.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">922</td>
    <td><a href="https://leetcode.com/problems/sort-array-by-parity-ii/">Sort Array By Parity II</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/922.%20Sort%20Array%20By%20Parity%20II/SortArrayByParityII.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">923</td>
    <td><a href="https://leetcode.com/problems/3sum-with-multiplicity/">3Sum With Multiplicity</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Sorting_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#counting">Counting</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_Counting.java"><em>Counting</em></a>
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/923.%203Sum%20With%20Multiplicity/ThreeSumWithMultiplicity_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">948</td>
    <td><a href="https://leetcode.com/problems/bag-of-tokens/">Bag of Tokens</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/948.%20Bag%20of%20Tokens/BagOfTokens.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#greedy">Greedy</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">977</td>
    <td><a href="https://leetcode.com/problems/squares-of-a-sorted-array/">Squares of a Sorted Array</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/977.%20Squares%20of%20a%20Sorted%20Array/SquaresOfASortedArray_Sorting.java"><em>Sorting</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1089</td>
    <td><a href="https://leetcode.com/problems/duplicate-zeros/">Duplicate Zeros</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1089.%20Duplicate%20Zeros/DuplicateZeros_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1089.%20Duplicate%20Zeros/DuplicateZeros.java"><em>Without Two Pointers</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1346</td>
    <td><a href="https://leetcode.com/problems/check-if-n-and-its-double-exist/">Check If N and Its Double Exist</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#binary-search">Binary Search</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_Sorting_BinarySearch.java"><em>Binary Search & Sorting</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1346.%20Check%20If%20N%20and%20Its%20Double%20Exist/CheckIfNAndItsDoubleExist_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1679</td>
    <td><a href="https://leetcode.com/problems/max-number-of-k-sum-pairs/">Max Number of K-Sum Pairs</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_Sorting_TwoPointers.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#hash-table">Hash Table</a>,
      <a href="#sorting">Sorting</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1679.%20Max%20Number%20of%20K-Sum%20Pairs/MaxNumberOfKSumPairs_HashTable.java"><em>Hash Table</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">2095</td>
    <td><a href="https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list/">Delete the Middle Node of a Linked List</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2095.%20Delete%20the%20Middle%20Node%20of%20a%20Linked%20List/DeleteTheMiddleNodeOfALinkedList.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">2130</td>
    <td><a href="https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/">Maximum Twin Sum of a Linked List</a></td>
    <td align="center">Java with
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers.java">Two Pointers</a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/2130.%20Maximum%20Twin%20Sum%20of%20a%20Linked%20List/MaximumTwinSumOfALinkedList_TwoPointers_Stack.java">Two Pointers & Stack</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#linked-list">Linked List</a>,
      <a href="#stack">Stack</a>,
      <a href="#two-pointers">Two Pointers</a>
    </td>
    <td></td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>

<details><summary><h3 id="union-find">Union Find</h3></summary>
<table>
  <tr>
    <th>#</th>
    <th>Problem</th>
    <th>Solution</th>
    <th>Difficulty</th>
    <th>Topics</th>
    <th>Note</th>
  </tr>
  <tr>
    <td align="center">130</td>
    <td><a href="https://leetcode.com/problems/surrounded-regions/">Surrounded Regions</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_UnionFind.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_BFS.java"><em>Breadth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/130.%20Surrounded%20Regions/SurroundedRegions_DFS.java"><em>Depth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">200</td>
    <td><a href="https://leetcode.com/problems/number-of-islands/">Number of Islands</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_UnionFind.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#array">Array</a>,
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#matrix">Matrix</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_BFS.java"><em>Breadth-First Search</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/200.%20Number%20of%20Islands/NumberOfIslands_DFS.java"><em>Depth-First Search</em></a>
    </td>
  </tr>
  <tr>
    <td align="center">1061</td>
    <td><a href="https://leetcode.com/problems/lexicographically-smallest-equivalent-string/">Lexicographically Smallest Equivalent String</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1061.%20Lexicographically%20Smallest%20Equivalent%20String/LexicographicallySmallestEquivalentString.java">Java</a>
    </td>
    <td align="center">$\text{\color{Dandelion}Medium}$</td>
    <td align="center">
      <a href="#string">String</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td></td>
  </tr>
  <tr>
    <td align="center">1971</td>
    <td><a href="https://leetcode.com/problems/find-if-path-exists-in-graph/">Find if Path Exists in Graph</a></td>
    <td align="center">
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_UnionFind.java">Java</a>
    </td>
    <td align="center">$\text{\color{TealBlue}Easy}$</td>
    <td align="center">
      <a href="#breadth-first-search">Breadth-First Search</a>,
      <a href="#depth-first-search">Depth-First Search</a>,
      <a href="#graph">Graph</a>,
      <a href="#union-find">Union Find</a>
    </td>
    <td>Solution Using
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_BFS.java"><em>Breadth-First Search</em></a>,
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Iterative.java"><em>Depth-First Search (Iterative)</em></a> or
      <a href="https://github.com/cheehwatang/leetcode-java/blob/main/solutions/1971.%20Find%20if%20Path%20Exists%20in%20Graph/FindIfPathExistsInGraph_DFS_Recursive.java"><em>Depth-First Search (Recursive)</em></a>
    </td>
  </tr>
</table>
<p align="right"><a href="#topics"> :arrow_up:<b>Back To Top</b></a></p>
<hr>
</details>