Compilare: user.c: In function ‘main’: user.c:101: warning: unused variable ‘last’ user.c:49: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:50: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:54: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:60: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:74: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:80: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result