func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int T;     scanf( %d , &T);     while (T--) {       int n, ans = 0;       scanf( %d , &n);       map<string, int> book;       vector<string> aa, temp;       for (int i = 1; i <= n; i++) {         string s;         cin >> s;         book[s] = 1;         temp.push_back(s);       }       for (vector<string>::iterator it = temp.begin(); it < temp.end(); it++) {         string s;         s = *it;         if (book[s] == 1) {           book[s]++;           aa.push_back(s);         } else {           for (int i = 0; i <= 9; i++) {             s[3] = i +  0 ;             if (!book.count(s)) {               book[s] = 1;               aa.push_back(s);               break;             }           }           ans++;         }       }       printf( %d n , ans);       for (vector<string>::iterator it = aa.begin(); it < aa.end(); it++)         cout << *it << endl;     }   }   