【LeetCode】39. 组合总和

class Solution {
private:
    vector<vector<int>> ans;
    vector<int> candidates;
    vector<int> path;
    void DFS(int start,int target){
        if(target == 0)ans.push_back(path);
        else {
            for(int i=start;i<candidates.size()&& target - candidates[i] >= 0;i++){
                path.push_back(candidates[i]);
                DFS(i,target-candidates[i]);
                path.pop_back();
            }
        }
    }
public:
    vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
        //if(candidates.size()==0){return ans;}
        sort(candidates.begin(),candidates.end());
        this->candidates = candidates;
        DFS(0,target);
        return ans;
    }
};