vector<vector<int> > permuteUnique(vector<int> &num) {

if(num.size()==0) {

return vector<vector<int> >();

}

vector<vector<int> > vs = permute(num, (int)num.size()-1);

set<vector<int> > se(vs.begin(), vs.end());

return vector<vector<int>>(se.begin(), se.end());

}

vector<vector<int> > permute(vector<int> &num, int n) {

vector<vector<int> > res;

if(n==0) {

res.push_back(vector<int>{num[0]});

return res;

}

vector<vector<int> > ps = permute(num, n-1);

for(int i=0;i<ps.size();i++) {

for(int j=0;j<=n;j++){

if(j!=n) {

if(ps[i][j]==num[n]) {

continue;

}

}

vector<int> t(ps[i].begin(), ps[i].end());

t.insert(t.begin()+j,num[n]);

res.push_back(t);

}

}

return res;

}