Implement Double Linked List from Stack

   Imagine all items are organized into two stacks,one of them is head stack,and the other one is tail stack:

For Example:

    head : 1,2,3,4->

    tail     : <-5,6,7,8

now u can move 4 to 5:

    head : 3,2,1->

    tail     : <-4,5,6,7,8

or u can move 5 to 4;

    head : 5,4,3,2,1->

    tail     : <-6,7,8

and them i will give the java code below this

import java.util.Stack;class DoubleLinkedList{Stack<Integer> s;Stack<Integer> t;int count;DoubleLinkedList(){s = new Stack<Integer>();t = new Stack<Integer>();count = 0;}// insert an data into the tail of head stack // move all the item of head stack to tail stack and add countpublic void insertInBeginning(int data){while(!s.isEmpty()){t.push(s.pop());}s.push(data);count++;}// insert an data into the tail of tail stack // move all the item of tail stack to head stack and add countpublic void insertAtEnd(int data){while(!t.isEmpty()){s.push(t.pop());}t.push(data);count++;}// if tail stack != null ,remove the top item of tail stack,and put it into head stackpublic void moveForward(){while(!t.isEmpty()){int temp = t.pop();System.out.println(temp);s.push(temp);}}// if head stack!=null, remove the top item of head stack and put it into tail stackpublic void moveBackward(){while(!s.isEmpty()){int temp = s.pop();System.out.println(temp);t.push(temp);}}// iterat item from head to tail,first move all the item of head stack to tail stack

// and then get the top item of tail stack , if it is equal to data ,remove it,if not remove it and put it to head stack public void delete(int data){while(!s.isEmpty()){t.push(s.pop());}while(!t.isEmpty()){if(t.peek() == data){t.pop();return;}else{s.push(t.pop());}}}// find out the buttom item of head stack and then remove it public void deleteFirst(){while(!s.isEmpty()){int temp = s.pop();if(s.peek() == null){return;}t.push(temp);}}// find out the buttom item of tail stack and then remove itpublic void deleteLast(){while(!t.isEmpty()){int temp = t.pop();if(t.peek() == null){return;}s.push(temp);}}}

class P2{public static void main(String args[]){DoubleLinkedList list = new DoubleLinkedList();list.insertInBeginning(4);list.insertInBeginning(3);list.insertInBeginning(2);list.insertInBeginning(1);list.insertAtEnd(5);list.insertAtEnd(6);list.insertAtEnd(7);list.moveBackward();list.moveForward();list.delete(5);list.moveBackward();list.moveForward();}}