Compilare: user.c: In function ‘main’: user.c:11:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("subbit.in","r",stdin); ^ user.c:12:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("subbit.out","w",stdout); ^ user.c:41:11: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%lld\n",p+1+10-k); ^