Compilare: user.c: In function ‘main’: user.c:46:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen (IN, "r", stdin); ^ user.c:47:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen (OUT, "w", stdout); ^ user.c: In function ‘read’: user.c:14:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.c:16:15: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &v[i]); ^