func_code_string: #include <bits/stdc++.h>   using namespace std;   long long MOD = 1e9 + 7;   long long a = 0;   long long b = 0;   void dfs(vector<vector<int>> &g, vector<bool> was, int v, int lvl) {     was[v] = true;     if (lvl % 2 == 0)       a++;     else       b++;     for (int x : g[v]) {       if (!was[x]) dfs(g, was, x, lvl + 1);     }   }   int main() {     int n;     cin >> n;     unordered_set<string> names;     for (int i = 0; i < n; i++) {       string s;       cin >> s;       if (names.find(s) == names.end())         cout <<  NO  << endl;       else         cout <<  YES  << endl;       names.insert(s);     }     return 0;   }   