public IEnumerable <T> BackEnumerator()
{
DoublyNode <T> current = tail;
while (current != null)
{
yield return(current.Data);
current = current.Previous;
}
}
IEnumerator <T> IEnumerable <T> .GetEnumerator()
{
DoublyNode <T> current = head;
while (current != null)
{
yield return(current.Data);
current = current.Next;
}
}
// Удаление из начала очереди
public T popFront()
{
if (size == 0)
{
throw new InvalidOperationException();
}
T output = head.Data;
head = head.Next;
size--;
return(output);
}
// Удаление из конца очереди
public T popBack()
{
if (size == 0)
{
throw new InvalidOperationException();
}
T output = tail.Data;
tail = tail.Previous;
tail.Next = null;
size--;
return(output);
}
private DoublyNode <T> tail; // последний/хвостовой элемент
// Добавление элемента в конец
public void pushBack(T data)
{
DoublyNode <T> node = new DoublyNode <T>(data);
if (head == null)
{
head = node;
}
else
{
tail.Next = node;
node.Previous = tail;
}
tail = node;
size++;
}
// Добавление элемента в начало
public void pushFront(T data)
{
DoublyNode <T> node = new DoublyNode <T>(data);
DoublyNode <T> temp = head;
node.Next = temp;
head = node;
if (size == 0)
{
tail = head;
}
else
{
temp.Previous = node;
}
size++;
}
// Очищение очереди
public void Clear()
{
head = null;
tail = null;
size = 0;
}