Compilare: user.c: In function ‘main’: user.c:72: warning: unused variable ‘j’ user.c:73: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:74: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:75: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:79: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:82: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:88: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result