LeetCode OJ Subsets

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

Note:

• Elements in a subset must be in non-descending order.
• The solution set must not contain duplicate subsets.

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

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

This problem has been solved in subsets 2.

class Solution {public:    vector<vector<int> > subsets(vector<int> &S) {        sort(S.begin(), S.end());        vector<vector<int> > result(1);        int oldval=S[0];        int oldj=0;        for(int i=0; i<S.size(); i++){            int temp=oldj;            if(S[i]!=oldval){                oldval=S[i]; temp=0;            }            int j=result.size();            oldj=j;            while(j-->temp){                result.push_back(result[j]);                result.back().push_back(S[i]);            }        }        return result;    }};