Subsets

//78. Subsets

Given a set of distinct integers, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,
If nums = [1,2,3], a solution is:

[
[3],
[1],
[2],
[1,2,3],
[1,3],
[2,3],
[1,2],
[]
]

#include 
#include 

using namespace std;

class Solution {
public:
    vector > subsets(vector& nums) {
        
        res.clear();
        if(nums.size()==0){
            return res;
        }
        vector s;
        for(int i=0;i > res;
    //s saved 0---start-1,nums ，search new element from start
    void findNext(vector& nums,int start,int k,vector& s){
        if(s.size()==k){
            res.push_back(s);
            return;
        }

        for(int i=start;i nums(arr,arr+sizeof(arr)/sizeof(int));
    vector > res=Solution().subsets(nums);
    for(int i=0;i