Compilare: user.c: In function ‘main’: user.c:15:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sushi.in", "r", stdin); ^ user.c:16:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("sushi.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:22:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.c: In function ‘sushi’: user.c:11:2: warning: ‘S’ may be used uninitialized in this function [-Wmaybe-uninitialized] return S; ^ user.c: In function ‘main’: user.c:20:16: warning: ‘i’ may be used uninitialized in this function [-Wmaybe-uninitialized] assert(i >= 0 && i < n); ^