Solution Backtracking 1

[shakthinandana]

No description provided.

[super30admin]

Combination Sum (combination-sum.py)

Strengths:

• Correct backtracking implementation with proper path restoration using path.pop()
• Clean and readable code structure
• Efficient memory usage by modifying path in-place rather than creating deep copies
• Proper handling of all base cases

Areas for Improvement:

• Time complexity analysis is imprecise - should be O(2^n) where n is the number of candidates, or more precisely O(k * 2^n) where k is the average solution length
• Space complexity analysis is incorrect - should be O(target/min(candidate)) for recursion depth
• The comment "#logic" is vague; consider renaming to "#choose" for consistency with the problem domain

Minor Issue:

• The solution doesn't sort candidates, which doesn't affect correctness but could enable early pruning if target becomes negative (though the current implementation handles this correctly anyway).

VERDICT: PASS

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Operations and expressions (expression-add-operators.py)

Strengths:

• Correct implementation of the backtracking algorithm with proper operator precedence handling for multiplication
• Clean backtracking implementation with proper path restoration using pop()
• Good handling of edge cases like leading zeros
• Well-structured code with clear separation between base case and recursive logic
• Good variable naming (pivot, calc, tail) that matches the problem's requirements

Areas for Improvement:

• The comments could be more descriptive, especially explaining the multiplication formula calc-tail+tail*curr
• Consider using StringBuilder for potentially better performance in string concatenation
• Could add early termination conditions if needed for optimization

The solution is functionally correct and follows the same approach as the reference solution. It handles all the test cases properly.

VERDICT: PASS