Compilare: user.c: In function ‘main’: user.c:56: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:57: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:61: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:64: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:69: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result