【回溯】40. Combination Sum II

与 Combination Sum同理：

class Solution {
public:
    vector<vector<int>> ans;
    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {
        vector<int> nums;
        sort(candidates.begin(),candidates.end());
        find(candidates,nums,target,0);
        
        return ans;
        
    }
    
    void find(vector<int>& candidates, vector<int> nums,int target,int m)
    {
        if(target <= 0)
        {
           if(target == 0)
                ans.push_back(nums);
           return ;
        }     
        
        for(int i=m;i<candidates.size();i++)
        {
            if(i>m&&candidates[i]==candidates[i-1])  //剔除重复
                continue;
           
            nums.push_back(candidates[i]);
            find(candidates,nums,target-candidates[i],i+1);
            nums.pop_back();
            
        }
    }
};