Completed Trees 3

[sanjoli97]

No description provided.

[super30admin]

Path Sum II (PathSum2.java)

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Your solution demonstrates a solid understanding of the backtracking pattern for tree traversal problems. The implementation is correct and efficient. Here are some suggestions for improvement:

1. Clarify space complexity comments: Your comment "SC = O(h)" is incomplete. While the recursion stack is O(h), you also store all valid paths in result, which in the worst case could be O(n * h). Consider updating your comment to reflect the complete space complexity.

2. Better variable naming: Consider renaming list to currentPath or path for better readability and to avoid confusion with the List interface.

3. Add early return for null root: While your code handles null root correctly in the dfs method, adding a check at the beginning of pathSum could make the intent clearer.

4. Consider edge case handling: Your solution correctly handles the case where targetSum becomes negative (since node values can be negative), but you might want to add a comment explaining this.

Overall, this is a well-structured solution that correctly solves the problem. The backtracking implementation is clean and efficient.

**

VERDICT: PASS

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Symmetric Tree (SymmetricTree.java)

Strengths:

• Excellent implementation that mirrors the reference solution's approach
• Well-documented with clear comments explaining the BFS strategy
• Proper handling of all null cases and value comparisons
• Clean, readable code structure

Areas for Improvement:

• The solution is already well-optimized. One minor suggestion: you could add an early check for root == null at the beginning for clarity, though it's not strictly necessary given the problem constraints.
• Consider adding a brief comment about why we add root twice (to compare the tree with itself in mirrored fashion).

The solution demonstrates a solid understanding of the problem and correctly implements an efficient iterative solution.

VERDICT: PASS