public static ListNode <T> Sort <T>(ListNode <T> head)
{
ListNode <T>[] sorted = LinkedListUtilities.Enumerate(head).OrderBy(o => o.Value).ToArray();
ListNode <T> sentinel = new ListNode <T>();
ListNode <T> tail = sentinel;
foreach (ListNode <T> current in sorted)
{
tail.Next = current;
current.Previous = tail;
tail = current;
}
sentinel.Next.Previous = null;
return(sentinel.Next);
}
public static T[] ToArray <T>(ListNode <T> head)
{
return(LinkedListUtilities.Enumerate(head).Select(o => o.Value).ToArray());
}
public static void Append <T>(ListNode <T> a, ListNode <T> b)
{
ListNode <T> tail = LinkedListUtilities.Tail(a);
tail.Next = b;
}