func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       string s[n];       map<string, int> m;       set<string> k;       int count = 0;       for (int i = 0; i < n; i++) {         cin >> s[i];         k.insert(s[i]);       }       for (int i = 0; i < n; i++) {         if (m[s[i]] >= 1) {           count++;           int j = 0;           while (k.find(s[i]) != k.end()) {             s[i][3] = j +  0 ;             j++;           }         }         m[s[i]]++;         k.insert(s[i]);       }       cout << count << endl;       for (int i = 0; i < n; i++) cout << s[i] << endl;     }     return 0;   }   