Compilare: user.c: In function ‘main’: user.c:84: warning: unused variable ‘k’ user.c:81: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:82: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:85: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:89: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:94: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:96: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result