add binary-search-1 solutions

[nikhylw]

No description provided.

[super30admin]

Search inside a Rotated Sorted Array (solution1.py)

The binary search implementation for the 2D matrix problem is well-structured and follows best practices. However, you submitted code for the wrong problem. The "Search in Rotated Sorted Array" problem requires handling a single rotated array where you need to determine which half is sorted at each step and adjust your search accordingly. Your current solution treats the input as a 2D matrix and flattens it for binary search, which is a different algorithm entirely. Please implement the solution for the rotated sorted array problem using the standard approach: at each step, determine whether the left or right half is sorted, then check which half the target could be in based on the sorted half's bounds.

VERDICT: NEEDS_IMPROVEMENT

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Search Inside a Sorted Array whose Length is unknown (solution2.py)

The student appears to have implemented a solution for a different problem (search in rotated sorted array). To improve:

1. Understand the problem requirements: The key challenge here is dealing with an array of unknown size. You must use the ArrayReader.get(i) interface to access elements, and handle the case where i is out of bounds (returns 2^31 - 1).

2. Two-phase approach: First, find the search bounds by exponentially expanding (doubling high until you find a value >= target or hit the boundary). Then perform binary search within those bounds.

3. Interface usage: Replace direct array access (nums[mid]) with reader.get(mid) calls.

4. Remove irrelevant logic: The rotated array check (nums[low] <= nums[mid]) is not needed for a standard sorted array.

STRENGTHS:

• The binary search implementation within the found range is correct
• Good variable naming and code structure
• Proper handling of edge cases in binary search

NEEDS_IMPROVEMENT:

• The solution addresses a different problem entirely
• Missing the core concept of searching in an unknown-size array
• Not using the provided ArrayReader interface

VERDICT: NEEDS_IMPROVEMENT

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Search a 2D Matrix (solution3.py)

Strengths:

• Clean, well-structured code with meaningful variable names
• Correct implementation of exponential search pattern
• Proper handling of edge cases (checking if low equals target at the end)
• Efficient O(1) space complexity

Areas for Improvement:

• The solution addresses a different problem (ArrayReader with infinite sorted array) rather than the 2D matrix search problem described
• The function signature doesn't match the problem requirements (searchMatrix(int[][] matrix, int target))
• For the actual 2D matrix problem, a simple binary search treating the 2D array as 1D would be more appropriate

Note: If this is actually a different LeetCode problem (like "Search in a Sorted Array of Unknown Length" - LeetCode 702), then the solution is correct. However, based on the provided problem statement about a 2D matrix, this solution doesn't match the requirements.

VERDICT: NEEDS_IMPROVEMENT