Completed combination sum

[neel-dabhi]

No description provided.

[super30admin]

The student's solution demonstrates a good understanding of backtracking to solve the combination sum problem. Here are the key points:

1. Correctness: The solution correctly implements the backtracking approach to find all combinations of candidates that sum to the target. It handles both the "choose" and "don't choose" cases appropriately.

2. Time Complexity: The student correctly identifies the time complexity as O(2^T), where T is the target. This is because in the worst case, we might explore all possible combinations (exponential time).

3. Space Complexity: The space complexity is correctly noted as O(N x T), where N is the number of candidates. This accounts for the recursion stack and the space needed to store combinations.

4. Code Quality: The code is well-structured and readable. The use of helper methods and clear comments for "choose" and "not choose" cases improves understanding. However, the method could benefit from:

   • More descriptive variable names (e.g., 'path' could be 'currentCombination')
   • Adding comments to explain the base cases
   • Making the helper method private (which it is) is a good practice

5. Efficiency: The solution is efficient for the problem constraints. One potential optimization could be to sort the candidates first and break early if the remaining target is less than the current candidate, but this isn't necessary for correctness.

The solution handles edge cases well, including when the target is 0 (empty combination) and when no combinations are possible.