Compilare: user.c: In function ‘main’: user.c:56:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("speculum.in", "r", stdin); ^ user.c:57:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("speculum.out", "w", stdout); ^ user.c:80:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &t); ^ user.c:84:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i%i", &x1, &y1, &x2, &y2); ^