Compilare: user.c: In function ‘sort’: user.c:57:34: warning: operation on ‘j’ may be undefined [-Wsequence-point] arr[j + 1] = arr[j--]; ^ user.c: In function ‘read’: user.c:27:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r", stdin); ^ user.c:29:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.c:31:34: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] for(i = 0; i < n; i++) scanf("%d", &arr[i]); ^ user.c: In function ‘write’: user.c:38:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT, "w", stdout); ^