/// <summary>
/// Adds a new node containing the specified value before the specified existing node in the <see cref="DoublyLinkedList{T}"/>.
/// </summary>
/// <param name="node">The <see cref="DoublyLinkedListNode{T}"/> before which to insert a new <see cref="DoublyLinkedListNode{T}"/> containing the value.</param>
/// <param name="value">The value to add to the <see cref="DoublyLinkedList{T}"/>.</param>
/// <returns>The new <see cref="DoublyLinkedListNode{T}"/> containing the value.</returns>
public DoublyLinkedListNode <T> AddBefore(DoublyLinkedListNode <T> node, T value)
{
if (node == null)
{
throw new ArgumentNullException(nameof(node));
}
if (node.List != this)
{
throw new InvalidOperationException("node doesn't belong to this list");
}
if (node == First)
{
return(AddFirst(value));
}
var newNode = new DoublyLinkedListNode <T>(value);
AddBefore(node, newNode);
return(newNode);
}
/// <summary>
/// Adds the specified new node at the end of the <see cref="DoublyLinkedList{T}"/>.
/// </summary>
/// <param name="node">The new <see cref="DoublyLinkedListNode{T}"/> to add at the end of the <see cref="DoublyLinkedList{T}"/>.</param>
public void AddLast(DoublyLinkedListNode <T> node)
{
if (node == null)
{
throw new ArgumentNullException(nameof(node));
}
if (node.List != null)
{
throw new InvalidOperationException("node belongs to another list");
}
if (Count == 0)
{
AddFirst(node);
return;
}
node.List = this;
node.Next = null;
node.Previous = Last;
Last.Next = node;
Last = node;
Count++;
}