Compilare: user.c: In function ‘main’: user.c:11:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.in", "r", stdin); ^ user.c:12:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.out", "w", stdout); ^ user.c:18:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld", &t); ^ user.c:20:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld", &a, &b); ^