Combination Sum II
问题：
Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
Each number in C may only be used once in the combination.
Note:
思路：
常见的回溯问题
我的代码：
public class Solution { public List<List<Integer>> combinationSum2(int[] num, int target) { if(num == null || num.length == 0) return rst; List<Integer> list = new ArrayList<Integer>(); Arrays.sort(num); helper(list, num, target, 0, 0); return rst; } private List<List<Integer>> rst = new ArrayList<List<Integer>>(); public void helper(List<Integer> list, int[] candidates, int target, int sum, int start) { if(sum > target) return; if(sum == target) { if(!rst.contains(list)) rst.add(new ArrayList(list)); return; } for(int i = start ; i < candidates.length; i++) { list.add(candidates[i]); helper(list, candidates, target, sum + candidates[i], i + 1); list.remove(list.size() - 1); } } }
原文：http://www.cnblogs.com/sunshisonghit/p/4326331.html
