Compilare: user.cpp: In function ‘int main()’: user.cpp:15: warning: statement has no effect user.cpp:17: warning: statement has no effect user.cpp:35: warning: statement has no effect user.cpp:37: warning: statement has no effect user.cpp:58: warning: statement has no effect user.cpp:60: warning: statement has no effect user.cpp:5: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:6: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result