func_code_string: #include <bits/stdc++.h>   using namespace std;   string str;   set<string> vis;   int main() {     int n;     scanf( %d , &n);     vis.clear();     for (int i = 0; i < n; ++i) {       cin >> str;       if (vis.find(str) != vis.end())         cout <<  YES  << endl;       else         cout <<  NO  << endl;       vis.insert(str);     }     return 0;   }   