public void TraverseBack(DLinkedList node)
{
if (node == null)
{
node = this;
}
System.Console.WriteLine("Traversing in Backward Direction");
while (node != null)
{
System.Console.WriteLine(node.data);
node = node.prev;
}
}
public void TraverseFront(DLinkedList node)
{
if (node == null)
{
node = this;
}
System.Console.WriteLine("Traversing in Forward Direction");
while (node != null)
{
System.Console.WriteLine(node.data);
node = node.next;
}
}
static void Main(string[] args)
{
DLinkedList node1 = new DLinkedList(1);
DLinkedList node3 = node1.InsertNext(3);
DLinkedList node2 = node3.InsertPrev(2);
DLinkedList node5 = node3.InsertNext(5);
DLinkedList node4 = node5.InsertPrev(4);
node1.TraverseFront();
node5.TraverseBack();
}
public DLinkedList InsertPrev(int value)
{
DLinkedList node = new DLinkedList(value);
if (this.prev == null)
{
node.prev = null; // already set on constructor
node.next = this;
this.prev = node;
}
else
{
// Insert in the middle
DLinkedList temp = this.prev;
node.prev = temp;
node.next = this;
this.prev = node;
temp.next = node;
// temp.prev does not have to be changed
}
return(node);
}
public DLinkedList InsertNext(int value)
{
DLinkedList node = new DLinkedList(value);
if (this.next == null)
{
// Easy to handle
node.prev = this;
node.next = null; // already set in constructor
this.next = node;
}
else
{
// Insert in the middle
DLinkedList temp = this.next;
node.prev = this;
node.next = temp;
this.next = node;
temp.prev = node;
// temp.next does not have to be changed
}
return(node);
}
public DLinkedList(int value)
{
data = value;
next = null;
prev = null;
}
public DLinkedList()
{
data = 0;
next = null;
prev = null;
}