public void AddAtHead(int val)
{
if (Value != -1)
{
var oldHead = new MyDoublyLinkedList(Value);
var next = Next;
if (next != null)
{
next.Prev = oldHead;
}
oldHead.Next = Next;
oldHead.Prev = this;
Value = val;
Next = oldHead;
Prev = null;
}
else
{
Value = val;
Prev = null;
Next = null;
}
}
public void AddAtIndex(int index, int val)
{
if (index > this.GetLength())
{
return;
}
if (index == 0)
{
AddAtHead(val);
return;
}
var prev = this.GetNodeAtIndex(index - 1);
var element = new MyDoublyLinkedList(val)
{
Prev = prev
};
var next = prev.Next;
if (next != null)
{
next.Prev = element;
}
element.Next = prev.Next;
prev.Next = element;
}
public static IEnumerable <int> ValuesToFlatList(this MyDoublyLinkedList head)
{
var result = new List <int>();
while (head != null)
{
result.Add(head.Value);
head = head.Next;
}
return(result);
}
public static MyDoublyLinkedList GetTail(this MyDoublyLinkedList head)
{
var tail = head;
while (head != null)
{
tail = head;
head = head.Next;
}
return(tail);
}
public static int GetLength(this MyDoublyLinkedList head)
{
var length = 0;
while (head != null)
{
head = head.Next;
length++;
}
return(length);
}
public void AddAtTail(int val)
{
var newElement = new MyDoublyLinkedList(val);
var tail = this.GetTail();
if (tail.Value == -1)
{
Value = val;
return;
}
tail.Next = newElement;
newElement.Prev = tail;
}
public static MyDoublyLinkedList GetNodeAtIndex(this MyDoublyLinkedList current, int index)
{
if (index < 0)
{
return(null);
}
for (int i = 0; i < index; i++)
{
current = current.Next;
}
return(current);
}
