public void Add(T item)
{
if (this.head == null)
{
this.head = new CustomNode <T>(item);
this.tail = this.head;
}
else
{
var newItem = new CustomNode <T>(item, tail);
this.tail = newItem;
}
count++;
}
public void Remove(T item)
{
int currentIndex = 0;
var currentItem = this.head;
CustomNode <T> prevItem = null;
while (currentItem != null)
{
if ((currentItem.Element != null &&
currentItem.Element.Equals(item)) ||
(currentItem.Element == null) && (item == null))
{
break;
}
prevItem = currentItem;
currentItem = currentItem.Next;
currentIndex++;
}
if (currentItem != null)
{
count--;
if (count == 0)
{
this.head = null;
}
else if (prevItem == null)
{
this.head = currentItem.Next;
this.head.Previous = null;
}
else if (currentItem == tail)
{
currentItem.Previous.Next = null;
this.tail = currentItem.Previous;
}
else
{
currentItem.Previous.Next = currentItem.Next;
currentItem.Next.Previous = currentItem.Previous;
}
}
}
public void Insert(T item, int index)
{
if (index >= ++count || index < 0)
{
throw new ArgumentOutOfRangeException("Index out of range!");
}
count++;
var newItem = new CustomNode <T>(item);
int currentIndex = 0;
var currentItem = this.head;
CustomNode <T> prevItem = null;
while (currentIndex < index)
{
prevItem = currentItem;
currentItem = currentItem.Next;
currentIndex++;
}
if (index == 0)
{
newItem.Previous = this.head.Previous;
newItem.Next = this.head;
this.head.Previous = newItem;
this.head = newItem;
}
else if (index == count - 1)
{
newItem.Previous = this.tail;
this.tail.Next = newItem;
newItem = this.tail;
}
else
{
newItem.Next = prevItem.Next;
prevItem.Next = newItem;
newItem.Previous = currentItem.Previous;
currentItem.Previous = newItem;
}
}
public void RemoveAt(int index)
{
if (this.IndexIsOutOfRange(index))
{
throw new ArgumentOutOfRangeException("Index out of range!");
}
int currentIndex = 0;
var currentItem = this.head;
CustomNode <T> prevItem = null;
while (currentIndex < index)
{
prevItem = currentItem;
currentItem = currentItem.Next;
currentIndex++;
}
if (this.count == 0)
{
this.head = null;
}
else if (prevItem == null)
{
this.head = currentItem.Next;
this.head.Previous = null;
}
else if (index == count - 1)
{
prevItem.Next = currentItem.Next;
tail = prevItem;
currentItem = null;
}
else
{
prevItem.Next = currentItem.Next;
currentItem.Next.Previous = prevItem;
}
count--;
}
public CustomLinkedList()
{
this.head = null;
this.tail = null;
this.count = 0;
}
public void Clear()
{
this.head = null;
this.tail = null;
this.count = 0;
}
