Compilare: user.c: In function ‘main’: user.c:86: warning: unused variable ‘k’ user.c:83: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:84: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:87: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:91: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:113: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:115: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result