class Solution {
public:

    void fun (vector <vector <int>> &res , vector <int> &path, vector <int> &nums, int idx)
    {

        res.push_back (path);

        for (int i = idx ; i < nums.size(); i++)
        {
            path.push_back(nums[i]);
            fun (res , path , nums , i + 1);
            path.pop_back();

        }
    }
    vector<vector<int>> subsets(vector<int>& nums) {
        vector < vector <int> > res ;
        vector <int> path;
        fun (res , path, nums , 0);

        return res;
    }

};