Subsets & Combinations - Combination Sum (Reuse Allowed)
Consider the same code as above. What is the output when candidates = [1] and target = 0?
Consider the same code as above. What is the output when candidates = [1] and target = 0?
medium🧾 Code Trace Q4 of Q15
Step-by-Step Solution
Solution:
Step 1: Check base case when target=0
Backtracking adds path when total == target; initially total=0, so path=[] is added.Step 2: Verify if recursion continues
Since target=0, no further recursion; result contains [[]].Final Answer:
Option A -> Option AQuick Check:
Empty combination sums to zero -> [[]] [OK]
Quick Trick: Target zero means empty combination included [OK]
Common Mistakes:
MISTAKES- Returning empty list instead of [[]]
- Assuming error on zero target
Trap Explanation:
PITFALL- Candidates often miss that empty path is a valid combination summing to zero.
Interviewer Note:
CONTEXT- Tests handling of edge cases with zero target.
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