private void AddLast(DoubleLinkedNode <T> node)
{
if (IsEmpty)
{
Head = node;
}
else
{
Tail.Next = node;
node.Previous = Tail;
}
Tail = node;
Count++;
}
public void RemoveLast()
{
if (IsEmpty)
{
throw new InvalidOperationException();
}
if (Count == 1)
{
Head = null;
Tail = null;
}
else
{
Tail.Previous.Next = null; // null the last node
Tail = Tail.Previous; // shift the Tail (now it is the former penultimate node)
}
Count--;
}
public void RemoveFirst()
{
if (IsEmpty)
{
throw new InvalidOperationException();
}
Head = Head.Next;
Count--;
if (IsEmpty)
{
Tail = null;
}
else
{
Head.Previous = null;
}
}