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:
- 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] ]
Solution: //回溯,注意与上一个区分
class Solution { public: void combination(vector<int>& candidates,int target,vector<int>& tmp,vector<vector<int>>& myvec,int start){ if(!target){ myvec.push_back(tmp); return; } for(int i=start;i<candidates.size()&&candidates[i]<=target;i++){ tmp.push_back(candidates[i]); combination(candidates,target-candidates[i],tmp,myvec,i+1); tmp.pop_back(); while(candidates[i]==candidates[i+1]) i++; } } vector<vector<int>> combinationSum2(vector<int>& candidates, int target) { vector<vector<int>> myvec; vector<int> tmp; sort(candidates.begin(),candidates.end()); combination(candidates,target,tmp,myvec,0); return myvec; } };