IEnumerator <T> IEnumerable <T> .GetEnumerator()
{
DoublyNode <T> current = head;
while (current != null)
{
yield return(current.Data);
current = current.Next;
}
}
public IEnumerable <T> BackEnumerator() // перебор элементов списка с конца
{
DoublyNode <T> current = tail;
while (current != null)
{
yield return(current.Data);
current = current.Previous;
}
}
public bool Contains(T data)
{
DoublyNode <T> current = head;
while (current != null)
{
if (current.Data.Equals(data))
{
return(true);
}
current = current.Next;
}
return(false);
}
public void Add(T data)
{
DoublyNode <T> node = new DoublyNode <T>(data);
if (head == null)
{
head = node;
}
else
{
tail.Next = node;
node.Previous = tail;
}
tail = node;
count++;
}
public void AddFirst(T data)
{
DoublyNode <T> node = new DoublyNode <T>(data);
DoublyNode <T> temp = head;
node.Next = temp;
head = node;
if (count == 0)
{
tail = head;
}
else
{
temp.Previous = node;
}
count++;
}
private DoublyNode <T> GetNode(int index)
{
if (index < 0 || index >= Count)
{
throw new IndexOutOfRangeException($"Index {index} is invalid; Only {Count} elements exist");
}
DoublyNode <T> current = head;
int t = 0;
while (t < index)
{
current = current.Next;
t++;
}
return(current);
}
public void Remove(int index)
{
var node = GetNode(index);
if (head == node)
{
if (head.Next != null)
{
head.Next.Previous = null;
head = head.Next;
}
else
{
head = null;
}
}
else if (tail == node)
{
if (tail.Previous != null)
{
tail.Previous.Next = null;
tail = tail.Previous;
}
else
{
tail = null;
}
}
else
{
node.Previous.Next = node.Next;
node.Next.Previous = node.Previous;
}
count--;
}
public void Clear()
{
head = null;
tail = null;
count = 0;
}