Combination Sum II — Java Coding Problem
Difficulty: medium | Category: backtracking
Problem Description
Given a collection of candidate numbers (`candidates`) and a target number (`target`), find all unique combinations in `candidates` where the candidate numbers sum to `target`. Each number in `candidates` may only be used **once** in the combination. **Note:** The solution set must not contain duplicate combinations. Sort first to skip duplicates.
Examples
Example 1
Input: candidates = [10,1,2,7,6,1,5], target = 8
Output: [[1,1,6],[1,2,5],[1,7],[2,6]]
Example 2
Input: candidates = [2,5,2,1,2], target = 5
Output: [[1,2,2],[5]]