public void Append(int value)
{
var node = new DoublyNode()
{
Value = value, Next = null, Previous = tail
};
tail.Next = node;
tail = node;
length++;
}
public void InsertLast(T t)
{
DoublyNode <T> newNode = new DoublyNode <T>()
{
Data = t
};
if (IsEmpty())
{
_first = newNode;
}
else
{
_last.Next = newNode;
newNode.Previous = _last;
}
_last = newNode;
}
public void DeleteLast()
{
if (!IsEmpty())
{
if (_first.Next == null)
{
_first = null;
}
else
{
_last.Previous.Next = null;
}
_last = _last.Previous;
}
else
{
throw new Exception("The list is empty!");
}
}
public void DeleteFirst()
{
if (!IsEmpty()) //
{
if (_first.Next == null) // if there is only one node in the list
{
_last = null;
}
else
{
_first.Next.Previous = null; // the list's first node will point to null
}
_first = _first.Next;
}
else
{
throw new Exception("The list is empty!");
}
}
public void InsertFirst(T t)
{
DoublyNode <T> newNode = new DoublyNode <T>()
{
Data = t
};
if (IsEmpty())
{
_last = newNode;
}
else
{
_first.Previous = newNode;
}
newNode.Next = _first; // newNode--> old first
_first = newNode; // first place
}
private void ActualInsert(int index, int value, DoublyNode currentNode)
{
for (int i = 0; i <= index; i++)
{
if (i == index - 1)
{
var node = new DoublyNode()
{
Value = value, Next = currentNode.Next, Previous = currentNode
};
currentNode.Next = node;
}
else
{
currentNode = currentNode.Next;
}
}
length++;
}
public DoublyLinkedListUser(List <int> values)
{
int i = 0;
foreach (var value in values)
{
if (i == 0)
{
head = new DoublyNode()
{
Value = value, Next = null, Previous = null
};
tail = head;
length = 1;
i++;
}
else
{
Append(value);
}
}
}
public void Remove(int index)
{
if (index > length - 1)
{
Console.Write("Invalid Index");
}
var currentNode = this.head;
DoublyNode node = new DoublyNode();
for (int i = 0; i <= index + 1; i++)
{
if (i == index - 1)
{
node = currentNode;
}
else if (i == index + 1)
{
node.Next = currentNode;
node.Previous = node;
}
currentNode = currentNode.Next;
}
length--;
}
public DoublyLinkedList()
{
_first = null;
_last = null;
}
