Eroare de compilare: user.cpp: In function 'int main()': user.cpp:23: error: 'ifstream' was not declared in this scope user.cpp:23: error: expected `;' before 'f' user.cpp:24: error: 'f' was not declared in this scope user.cpp:27: warning: comparison between signed and unsigned integer expressions user.cpp:48: error: 'ofstream' was not declared in this scope user.cpp:48: error: expected `;' before 'g' user.cpp:49: error: 'g' was not declared in this scope