Tree 3

[YogeshPardeshi]

No description provided.

[super30admin]

Root-to-leaf Sum II (Problem1.java)

Strengths:

1. Correctly implements backtracking pattern for tree traversal
2. Properly creates defensive copies when adding to result list
3. Clean base case handling for null nodes
4. Good variable scoping with appropriate use of local variables

Areas for Improvement:

1. The localResult parameter in helper method is redundant since it's already an instance variable - this adds confusion
2. Consider renaming variables for clarity: sum → currentSum, localResult → path
3. The backtracking could be more explicit by storing and restoring the size rather than removing elements
4. Consider adding null checks for edge cases (though the problem guarantees valid input)

Minor Optimization:
Instead of localResult.remove(localResult.size() - 1), you could use localResult.removeLast() in Java 21, or store the size before recursion and truncate: int size = localResult.size(); then localResult.subList(size, localResult.size()).clear(); or simply while (localResult.size() > size) localResult.remove(localResult.size() - 1);

VERDICT: PASS

---

Mirror Image of Itself Tree (Problem2.java)

Strengths:

• Correct recursive logic for checking mirror symmetry
• Good early termination with the flag variable
• Clean and readable code structure
• Efficient time complexity matching the optimal solution

Areas for Improvement:

• The flag approach works but returning a boolean directly from the helper method would be more idiomatic and cleaner
• Missing documentation/comments explaining the approach
• The TreeNode class definition is shown in comments but should be actual code for a complete solution
• Consider handling the case where left.val != right.val with an immediate return instead of just setting flag (though this works)

Minor Issue:

• The code structure is good, but the recursive approach could alternatively return true/false directly from the helper method, which some might consider cleaner than using a class-level flag variable.

VERDICT: PASS