LeetCode(90)-Subsets II 子集合之二

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],
[]
]

#include <iostream>
#include<vector>
using namespace std;
vector<int> input;
vector<vector<int>> ans;
vector<vector<int>> res;
vector<int> temp;
//遞歸方式
void getsubsets(vector<int> &S,int pos,int k){
    if(k<0) return;
    if(k==0){
        res.push_back(temp);
    }
    else{
        for(int i=pos;i<S.size();i++){
            temp.push_back(S[i]);
            getsubsets(S,pos+1,k-1);
            temp.pop_back();
            //重點
            while(i+1<S.size()&&S[i]==S[i+1])
            {  ++i;}
        }
    }

}
vector<vector<int> > subsetsWithDup(vector<int> &S) {
    sort(S.begin(), S.end());
    int size=S.size();
    for(int i=0;i<=size;i++){
        getsubsets(S,0,i);
    }
    return res;

}
int main(){
    int n,x;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>x;
        input.push_back(x);
    }
    ans=subsetsWithDup(input);
    for(int i=0;i<ans.size();i++){
        cout<<"[";
        for(int j=0;j<ans[i].size();j++){
            cout<<ans[i][j];
        }
        cout<<"]"<<endl;
    }
}