Compilare: user.c: In function ‘main’: user.c:24:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("fof.in", "r", stdin); ^ user.c:25:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("fof.out", "w", stdout); ^ user.c:28:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i", &n, &m); ^ user.c:33:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i", &x, &y); ^