Eroare de compilare: user.cpp:1:20: error: fstream.h: No such file or directory user.cpp: In function ‘int main()’: user.cpp:11: error: ‘ifstream’ was not declared in this scope user.cpp:11: error: expected ‘;’ before ‘f’ user.cpp:12: error: ‘ofstream’ was not declared in this scope user.cpp:12: error: expected ‘;’ before ‘g’ user.cpp:13: error: ‘f’ was not declared in this scope user.cpp:31: error: ‘abs’ was not declared in this scope user.cpp:34: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp:45: error: ‘g’ was not declared in this scope