public IEnumerable <T> BackEnumerator()
{
DoubleNode <T> current = tail;
while (current != null)
{
yield return(current.data);
current = current.Previous;
}
}
IEnumerator <T> IEnumerable <T> .GetEnumerator()
{
DoubleNode <T> current = head;
while (current != null)
{
yield return(current.data);
current = current.Next;
}
}
public bool Contains(T data)
{
DoubleNode <T> current = head;
while (current != null)
{
if (current.data.Equals(data))
{
return(true);
}
current = current.Next;
}
return(false);
}
public void Output()
{
if (IsEmpty)
{
Console.Write("Empty");
}
DoubleNode <T> node = head;
while (node != null)
{
Console.Write("{0} ", node.data);
node = node.Next;
}
Console.Write('\n');
}
int count; // количество элементов в списке
// добавление элемента
public void Add(T data)
{
DoubleNode <T> node = new DoubleNode <T>(data);
if (head == null)
{
head = node;
}
else
{
tail.Next = node;
node.Previous = tail;
}
tail = node;
count++;
}
public void AddFirst(T data)
{
DoubleNode <T> node = new DoubleNode <T>(data);
DoubleNode <T> temp = head;
node.Next = temp;
head = node;
if (count == 0)
{
tail = head;
}
else
{
temp.Previous = node;
}
count++;
}
// удаление
public bool Remove(T data)
{
DoubleNode <T> current = head;
// поиск удаляемого узла
while (current != null)
{
if (current.data.Equals(data))
{
break;
}
current = current.Next;
}
if (current != null)
{
// если узел не последний
if (current.Next != null)
{
current.Next.Previous = current.Previous;
}
else
{
// если последний, переустанавливаем tail
tail = current.Previous;
}
// если узел не первый
if (current.Previous != null)
{
current.Previous.Next = current.Next;
}
else
{
// если первый, переустанавливаем head
head = current.Next;
}
count--;
return(true);
}
return(false);
}
public int CompareTo(DoubleNode <T> other)
{
return(data.CompareTo(other.data));
}
public void Clear()
{
head = null;
tail = null;
count = 0;
}