[LeetCode] Subsets （bfs的vector实现）

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],
  []
]

class Solution {
public:
    vector<vector<int> > subsets(vector<int> &S) {
        vector<vector<int> > res;
        int len = S.size();
        vector<int> temp0,temp;
        res.push_back(temp);
        int start = 0,end = 1;
        
            
            while(start < end)
            {
                temp = res[start];
                temp0 = temp;
                start++;
                
                int n = 0;
                for(int i=0;i<len;i++){
                    if(find(temp.begin(),temp.end(),S[i])==temp.end()){
                        temp.push_back(S[i]);
                        sort(temp.begin(),temp.end());
                        if(find(res.begin(),res.end(),temp)==res.end()){
                           res.push_back(temp);
                           n++;
                        }    
                        temp = temp0;
                    }//end if
                }//end for
                end += n;
            }//end while
        return res;
    }//end func
};