Approach Summary
Sort candidates, then backtrack with a start index. Skip duplicates at the same recursion level so each element is used once.
How to Recognize This Pattern
- Duplicates in candidates — skip same value at same level
- Difference from Combination Sum: each number used once
Complexity Analysis
Time Complexity
O(2ⁿ)
Space Complexity
O(n)
Tags
Array Backtracking