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[yashhh-23]

No description provided.

[Copilot]

Pull request overview

Adds two Java solution implementations (likely for LeetCode-style graph/BFS problems): “The Maze” (rolling ball BFS) and “Find the Town Judge” (in/out-degree counting).

Changes:

• Added hasPath BFS implementation for a rolling-ball maze.
• Added findJudge implementation using indegree/outdegree arrays.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
maze.java	Introduces BFS-based rolling simulation to determine reachability in a maze.
findjugde.java	Introduces indegree/outdegree approach to identify the town judge node.

Suppressed comments (3)

maze.java:6

• This file uses Queue/LinkedList but doesn't import java.util types, and both added Java files declare a top-level Solution class in the default package. As-is, the project won't compile due to missing imports and duplicate class names. Add the needed imports and rename this class to a unique name.

class Solution {

findjugde.java:7

• This file also declares a top-level Solution class in the default package, which conflicts with maze.java's Solution class when compiled together. Rename the class to a unique name.

class Solution {

maze.java:12

• Edge case: when start equals destination, this implementation can return false if the ball can roll away in all directions (because it only checks the stop cell after rolling). Add an early return before BFS initialization.

    public boolean hasPath(int[][] maze, int[] start, int[] destination) {
        this.dirs = new int[][]{{-1,0},{1,0},{0,1},{0,-1}};
        this.m = maze.length;

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[super30admin]

Find the Town Judge (findjugde.java)

Strengths:

1. Clear approach: You correctly identified the in-degree/out-degree pattern, which is the optimal approach for this problem.
2. Good documentation: The comments at the top of the file clearly explain the time/space complexity and your thought process.
3. Readable code: Variable names are meaningful and the logic is easy to follow.
4. Correct handling of edge cases: The solution correctly handles the case where n = 1 (no trust relationships, person 1 is the judge).

Areas for improvement:

1. Space optimization: You could use a single array instead of two. For each trust relationship [a, b], do score[a]-- and score[b]++. Then the judge will have a score of n-1. This saves a small amount of memory.
2. Minor: The comment "having the thought of indegree and outdegree of the nodes" in the "Any problem you faced" section could be more descriptive about what specifically helped you arrive at the solution.

Overall, this is a solid solution that correctly solves the problem with optimal time complexity.

VERDICT: PASS

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The Maze (maze.java)

EJava code is well-structured and follows best practices. The BFS approach is correctly implemented with proper handling of the ball rolling mechanism. The visited marking using -1 is a good optimization to avoid using extra space. The code is essentially identical to the reference solution, just translated from C++ to Java. The student has provided clear comments explaining their approach and the time/space complexity analysis.

VERDICT: PASS