Compilare: user.cpp: In function ‘int main()’: user.cpp:23: warning: statement has no effect user.cpp:25: warning: statement has no effect user.cpp:35: warning: 3rd expression in for has no effect user.cpp:18: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:19: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result