Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:48: error: ‘fopen’ was not declared in this scope user.cpp:50: error: ‘fscanf’ was not declared in this scope user.cpp:53: error: ‘fgets’ was not declared in this scope user.cpp:54: error: ‘strlen’ was not declared in this scope user.cpp:57: error: ‘fclose’ was not declared in this scope user.cpp:65: error: ‘fgets’ was not declared in this scope user.cpp:66: error: ‘strlen’ was not declared in this scope user.cpp:82: error: ‘fprintf’ was not declared in this scope user.cpp:84: error: ‘fprintf’ was not declared in this scope