8.4 Power Set

Simple backtracking question.

    void getSubsets(vector<vector<int>>& result, vector<int>& nums, vector<int>& sub,int pos){        result.push_back(sub);        for (int i=pos; i<nums.size(); ++i) {            sub.push_back(nums[i]);            getSubsets(result, nums, sub, i+1);            sub.pop_back();        }    }    vector<vector<int>> subsets(vector<int>& nums) {        sort(nums.begin(), nums.end());        vector<vector<int>> result;        vector<int> sub;        getSubsets(result, nums, sub, 0);        return result;    }