Compilare: user.c: In function ‘dif’: user.c:9: warning: left-hand operand of comma expression has no effect user.c: In function ‘print’: user.c:74: warning: statement with no effect user.c: In function ‘main’: user.c:111: warning: unused variable ‘n’ user.c:108: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:109: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:114: 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 user.c:122: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result