LeetCode-Subsets II

Given a collection of integers that might contain duplicates, 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 = [1,2,2], a solution is:

[
  [2],
  [1],
  [1,2,2],
  [2,2],
  [1,2],
  []
]
普通遍历

class Solution {
public:
    vector<vector<int> > subsetsWithDup(vector<int> &S) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        set<vector<int> > res;
        vector<int> one;
        vector<int> oneone;
        int i;
        vector<int> check;
        for(i=0;i<S.size();i++)check.push_back(0);
        i=0;
        while(true){
            if(check[i]==2){
                i--;
                if(i<0)break;
                one.pop_back();
            }
            else{
                if(check[i]==1){
                    one.push_back(S[i]);
                }
                check[i]++;
                i++;
                if(i==S.size()){
                    oneone=one;
                    sort(oneone.begin(),oneone.end());
                    res.insert(oneone);
                    i--;
                }
                else{
                    check[i]=0;
                }
            }
            
        }
        set<vector<int> >::iterator it;
        vector<vector<int> > ret;
        for(it=res.begin();it!=res.end();it++){
            ret.push_back(*it);
        }
        return ret;
    }
};