40. Combination Sum II(重要)

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums toT.

Each number in C may only be used once in the combination.

Note:

• All numbers (including target) will be positive integers.
• The solution set must not contain duplicate combinations.

For example, given candidate set [10, 1, 2, 7, 6, 1, 5] and target 8, 

A solution set is: 

[
  [1, 7],
  [1, 2, 5],
  [2, 6],
  [1, 1, 6]
]

Each number in C may only be used once in the combination.

class Solution {
public:
	vector> combinationSum2(vector& candidates, int target) {
		sort(candidates.begin(), candidates.end());
		vectortmp;
		dfs(candidates, target, tmp, 0);
		return s;
	}
private:

	void dfs(vector& candidates, int target, vector&tmp,int cur){
		if (target < 0) return;
		if (target==0){
			s.push_back(tmp);
			return;
		}
		for (int i = cur; i < candidates.size(); i++){
			if (cur != i&&candidates[i] == candidates[i-1]) continue;//i-1,i
			tmp.push_back(candidates[i]);
			dfs(candidates, target-candidates[i], tmp,i+1);
			tmp.pop_back();
		}
	}

	vector > s;
};