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.
Input: candidates = [10,1,2,7,6,1,5], target = 8
Output: [[1,1,6],[1,2,5],[1,7],[2,6]]
Input: candidates = [2,5,2,1,2], target = 5
Output: [[1,2,2],[5]]