Compilare: user.c: In function ‘main’: user.c:15:8: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.c:16:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("pba.in", "r", stdin); ^ user.c:17:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("pba.out", "w", stdout); ^ user.c:19:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.c:21:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld", &v[i]); ^