/**
knakul853
**/
class Solution {
public:
    vector<vector<int>> subsets(vector<int>& nums) {

        vector<vector<int>>ans;
        vector<int>temp;
        sort(nums.begin(),nums.end());
        backtrack(nums , ans , 0 , temp);

        return ans;

    }

    void backtrack(vector<int>& nums , vector<vector<int> >& ans , int id , vector<int>&temp)
    {
            ans.push_back(temp);


        for(int i=id;i<nums.size();i++)
        {
            temp.push_back(nums[i]);
            backtrack(nums , ans , i+1 , temp);
            temp.pop_back();
        }
    }
};