Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:50: error: ‘itoa’ was not declared in this scope user.cpp:51: error: ‘strcat’ was not declared in this scope user.cpp:17: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result