Compilare: user.cpp: In function ‘void perm(int)’: user.cpp:15: warning: statement is a reference, not call, to function ‘afis’ user.cpp:15: warning: statement has no effect user.cpp: In function ‘int main()’: user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result