class Solution {
public:
    vector<int> a;
    bool f(int p,int left,vector<int>& c,vector<int>& ans)
    {
        if(left<0) return 0;
        if(left==0)
         return 1;
        //vector<int> a;
        if(f(p,left-c[p],c,ans)) a.push_back(c[p]);
        f(p+1,left-c[p],c,ans);
        f(p+1,left,c,ans);
        
        
    }
    vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
       vector<vector<int>> x;
        f(0,target,candidates,x);
        return x;
    }
};