Compilare: user.c: In function ‘main’: user.c:13:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sets.in", "r", stdin); ^ user.c:14:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sets.out", "w", stdout); ^ user.c:17:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &t); ^ user.c:20:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i", &n, &v); ^ user.c:23:38: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] for (i = 0; i < n; ++i) scanf("%i", &A[i]); ^