Compilare: user.c: In function ‘main’: user.c:53: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:54: 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:59: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result