[isSymmetric && pathSum ii]

[takchiks]

No description provided.

[super30admin]

Your solution is well-implemented and efficient. You used backtracking to manage the current path, which avoids unnecessary copying of the list at each recursive step. This is a good optimization.

However, here are a few suggestions for improvement:

• Rename the class to Solution to match the Leetcode requirement.
• Instead of using an instance variable ans, consider declaring it as a local variable in the pathSum method and passing it to the helper function. This makes the solution stateless and avoids potential issues if the same instance is reused (though Leetcode creates a new instance per test case).
• Remove the debug print statement for cleaner code.
• Use more descriptive variable names: tar could be renamed to targetSum for clarity.
• Add comments to explain the backtracking step (why we remove the last element) for better readability.

Your time and space complexity analysis is correct. The code is efficient and follows best practices for recursive tree traversal.