Completed Trees2

[Keerthi0910]

No description provided.

[super30admin]

Construct Binary Tree from Inorder and Postorder Traversal (Problem1.java)

1. Correctness: Your solution correctly solves the problem. The logic of using postorder to find the root and inorder to split into left/right subtrees is correctly implemented. The order of building right before left is correct since postIndex starts from the end.

2. Time Complexity: O(n) - matches the reference solution. Each node is visited once, and HashMap lookups are O(1) average.

3. Space Complexity: O(n) - matches the reference solution. The HashMap stores n entries, and the recursion stack can go up to O(n) in the worst case (skewed tree).

4. Code Quality: The code is well-structured and readable. Good use of comments explaining the approach. The variable naming is clear (postIndex, rootVal, rootIndex). The solution follows the same approach as the reference solution.

5. Efficiency: The solution is efficient. One minor optimization could be to make map and postIndex local to the method or pass them as parameters to avoid instance variables, but this is a stylistic choice.

Minor suggestions:

• The comment "Space Complexity O(n)" and "Time Complexity o(n)" have inconsistent capitalization (O vs o).
• Consider adding edge case handling or input validation.
• The helper method could be made private for better encapsulation.

Overall, the solution is correct, efficient, and well-implemented. It matches the reference solution in both approach and complexity.

VERDICT: PASS

---

Sum Root to Leaf Numbers (Problem2.java)

Your solution is correct and follows the same approach as the reference solution. Here are some points to consider:

Strengths:

• The logic is correct and the DFS approach is appropriate for this problem.
• The code is readable and well-structured.
• Time complexity is optimal at O(n).

Areas for Improvement:

1. Space Complexity Comment: You stated O(1) space complexity, but the actual space complexity is O(h) due to the recursive call stack. Be accurate in your comments.

2. Variable Initialization: It's good practice to explicitly initialize instance variables. Consider int sum = 0; instead of just int sum;.

3. State Reset: If you want to make the solution more robust, consider resetting sum = 0 at the beginning of sumNumbers() to handle cases where the method might be called multiple times on the same instance.

4. Indentation: The indentation for int sum; is slightly off. Make sure to maintain consistent indentation throughout.

5. Method Visibility: The helper method could be private to follow encapsulation best practices, as it's an internal helper method.

Overall, your solution is functionally correct and demonstrates a good understanding of the problem.

VERDICT: PASS