Eroare de compilare: user.cpp:1:21: error: iostream.h: No such file or directory user.cpp:2:21: error: fstream.h: No such file or directory user.cpp: In function ‘void back()’: user.cpp:30: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp: In function ‘int main()’: user.cpp:45: error: ‘ifstream’ was not declared in this scope user.cpp:45: error: expected ‘;’ before ‘f’ user.cpp:46: error: ‘ofstream’ was not declared in this scope user.cpp:46: error: expected ‘;’ before ‘g’ user.cpp:47: error: ‘f’ was not declared in this scope user.cpp:49: error: ‘g’ was not declared in this scope