Eroare de compilare: user.cpp: In function 'void df(long int)': user.cpp:6: error: 'muc' was not declared in this scope user.cpp:8: error: 'tata' was not declared in this scope user.cpp:9: error: 'niv' was not declared in this scope user.cpp: In function 'int main()': user.cpp:16: error: 'ifstream' was not declared in this scope user.cpp:16: error: expected `;' before 'q' user.cpp:17: error: 'ofstream' was not declared in this scope user.cpp:17: error: expected `;' before 'w' user.cpp:18: error: 'q' was not declared in this scope user.cpp:50: error: 'w' was not declared in this scope