Given a set of distinct integers, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: nums = [1,2,3]Output:[  [3],  [1],  [2],  [1,2,3],  [1,3],  [2,3],  [1,2],  []]

AC code:

class Solution {public:    vector
     
      
       > subsets(vector
       
        & nums) {        vector
        
         
          > res;        vector
          
            temp; int len = nums.size(); solve_subset(0, len, res, temp, nums); return res; } void solve_subset(int begin, int n, vector
           
            
             >& res, vector
             
              & temp, vector
              
               & nums) { res.push_back(temp); for (int i = begin; i < n; ++i) { temp.push_back(nums[i]); solve_subset(i+1, n, res, temp, nums); temp.pop_back(); } }};
              
             
            
           
          
         
        
       
      
     

Runtime: 4 ms, faster than 100.00% of C++ online submissions for Subsets.