78. Subsets

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],
  []
]


给定一组不同的整数nums，返回所有可能的子集

C++：

class Solution {
public:
    vector<vector<int>> subsets(vector<int>& nums) {
        vector<vector<int> > subs ;
        vector<int> sub ;
        subsets(nums,0,sub,subs) ;
        return subs ;
    }
    
    void subsets(vector<int>& nums , int start , vector<int>& sub , vector<vector<int> >& subs) {
        subs.push_back(sub) ;
        for(int i = start ; i < nums.size() ; i++){
            sub.push_back(nums[i]) ;
            subsets(nums,i+1,sub,subs) ;
            sub.pop_back() ;
        }
    }
};