public void Enqueue(T value)
{
var newNode = new QueueNode <T>(value);
if (this.Count == 0)
{
this.head = newNode;
}
else if (this.Count == 1)
{
this.tail = newNode;
this.tail.PreviousNode = this.head;
this.head.NextNode = this.tail;
}
else
{
this.tail.NextNode = newNode;
newNode.PreviousNode = this.tail;
this.tail = newNode;
}
this.Count++;
}
public T Dequeue()
{
if (this.Count == 0)
{
throw new InvalidOperationException("The queue is empty!");
}
var element = this.head.Value;
this.head = this.head.Next;
if (this.head == null)
{
this.tail = null;
}
else
{
this.head.Previous = null;
}
this.Count--;
return(element);
}
