12. Java implementation of doubly linked list

Schematic diagram:

Operation Result:

Node Code:

public class Node {
int data;
Node Next;
Node previous; Forward pointer

public Node (int value) {
TODO auto-generated Constructor stub
This.data = value;
}

public void display ()
{
System.out.print (data+ "");
}
}

Doublelinklist:

public class Doublelinklist {
Private Node first;
Private Node last; Tail knot Point

Public Doublelinklist () {
TODO auto-generated Constructor stub
First =null;
last = null;
}

public void Insertfirst (int value)//header inserted into
{
Node node = new node (value);
if (IsEmpty ())
{
First = node;
Last =node;
}
Else
{
Node.next = First;
first.previous = node;
First = node;

}

}

public void Insertlast (int value)//Insert node from tail
{
Node node = new node (value);
if (IsEmpty ())
{
First = node;
Last =node;
}
Else
{
Last.next =node;
Node.previous = Last;
last = node;
}
}

public void Deletefirst ()//Delete head node
{

if (First.next ==null)
{
First =null;
Last=null;
}
Else
{
Node tmp = First.next;
Tmp.previous =null;
first= tmp;
if (first = = null)
Last =null;
}

}

public void Deletelast ()//delete from tail
{
if (last.previous = = null)
{
Last =null;
First=null;
}
Else
{
Last.previous.next =null;
last = last.previous;
}

}


public void find (int value)//Find data
{
Node current = first;
while (current.data! = value)
{
Current =current.next;
}
Current.display ();
}

public void Finddelete (int value)//Find data and delete
{
Node current = first;

if (First.data ==value)
{
First =first.next;
}
Else
{
while (current.data! = value)
{
Current =current.next;
}
Current.previous.next = Current.next;
}




}

public boolean IsEmpty ()//Determine if the linked list is empty
{
return (first = = null);
}


public void display ()//Show All nodes
{
Node current = first;
while (current! = null)
{
Current.display ();
Current =current.next;
}
}


}

12. Java implementation of a doubly linked list