class Solution {
public:
    vector<vector<int>> combinationSum(vector<int>& candidates, int target) {


        vector<vector<int>>ans;
        vector<int>temp;
        backtrack(ans , candidates , target , 0 , temp);
        return ans;
    }

    void backtrack(vector<vector<int>>&ans , vector<int>&candidates , int target , int id , vector<int>&temp)
    {
        if(target == 0)
        {
            ans.push_back(temp);
            return;
        }

        for(int i=id;i<candidates.size();i++)
        {
            if(candidates[i]<=target)
            {
                temp.push_back(candidates[i]);

                backtrack(ans , candidates , target - candidates[i] , i , temp);
                temp.pop_back();
            }
        }

    }
};