Completed Backtracking-1

[Sanket-S-Kale]

No description provided.

[super30admin]

Combination Sum (Problem1.py)

Strengths:

• Excellent problem-solving approach with clear backtracking logic
• Comprehensive documentation explaining time and space complexity
• Proper handling of all edge cases
• Good code structure and readability
• Shows understanding of both recursive approaches (include/exclude vs for-loop)

Areas for Improvement:

• Replace copy.deepcopy(path) with list(path) - it's more efficient for lists of primitives and is the standard approach in competitive programming
• The nonlocal result, candidates declaration is unnecessary since you're not reassigning these variables, only mutating/reading them
• Consider adding early return optimization: check if target < candidates[index] before recursing to potentially skip branches faster

Minor Notes:

• The commented-out for-loop solution is also correct and potentially more intuitive for some programmers
• Both solutions are valid and well-implemented

VERDICT: PASS

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Expression Add Operators (Problem2.py)

Strengths:

1. Excellent documentation with detailed time and space complexity analysis
2. Clear variable naming that makes the code self-explanatory
3. Proper handling of edge cases (empty string check)
4. Correct implementation of multiplication precedence using the "tail" concept
5. Good use of comments to explain the logic for each operator choice

Areas for Improvement:

1. Consider using StringBuilder instead of string concatenation for better performance in Java/Python. In Python, while strings are immutable, using f-strings or joining lists can be more efficient.
2. The comment about space complexity could be more precise - the result list itself can grow to O(N * 4^N) in the worst case.

Overall, this is a solid solution that demonstrates a good understanding of the backtracking approach and operator precedence handling.

VERDICT: PASS