Tuesday, 21 August 2012

To implement doubled linked list


Program to implement Doubly Linked List

import java.io.*; 
import java.lang.*; 
import java.util.*;

class Nodetype
{
            int info;
            Nodetype right,left;
            Nodetype(int i)
            {
                        info=i;
                        right=null;
                        left=null;
            }}

class Operations
{
            Nodetype list=null;
            void display()
            {
                                                /*display all nodes*/
                        Nodetype t;
                        t=list;
                        if(t==null)
                                    System.out.println("\nThe linked list is empty");
                        else
                        {
                                    System.out.print("\nList");
                                    while(t!=null)
                                    {
                                                System.out.print("<==>|"+t.info+"|");
                                                t=t.right;
                                    }
                        }
            }                       /*end display*/

            void insertbeg(int x)
            {
                                                /*insert new element in the beginning of linked list*/
                        Nodetype q=new Nodetype(x);
                        q.info=x;
                        q.right=list;
                        list=q;
                        display();
            }                                   /*end insertbeg*/

            void deletebeg()
            {
                                                /*delete a node from the beginning of the linked list*/
                        int x;
                        Nodetype q;
                        q=list;
                        if(list==null)
                                    System.out.println("\nThe linked list is empty");
                        else
                        {
                                    x=q.info;
                                    list=q.right;
                                    (q.right).left=null;
                                    System.out.println("\n\nThe deleted element is "+x);
                                    display();
                        }
            }                                   /*end deletebeg*/

            void insertend(int x)
            {
                                                /*insert new element at the end of linked list*/
                        Nodetype temp;
                        Nodetype q=new Nodetype(x);
                        q.info=x;
                        q.right=null;
                        temp=list;
                        if(list==null)
                        {
                                    list=q;
                                    q.left=null;
                        }
                        else
                        {
                                    while(temp.right!=null)
                                                temp=temp.right;
                                    temp.right=q;
                                    q.left=temp;
                        }
                        display();
            }                                   /*end insertend*/

            void deleteend()
            {
                                                /*delete a node from the end of the linked list*/
                        Nodetype q,temp=null;
                        int x;
                        q=list;
                        if(list==null)
                                    System.out.println("\nThe linked list is empty");
                        else
                        {
                                    if(list.right==null)
                                                list=null;
                                    else
                        {
                                   
while(q.right!=null)
                                    {
                                                temp=q;
                                                q=q.right;
                                    }
                                    temp.right=null;
                        }
                        System.out.println("\n\nThe deleted element is "+q.info);
            }
            display();
}                                   /*end deleteend

void insright(int x,int nx)
{
                                                /*insert new element towards right of a  specific node*/
                        Nodetype r,t;
                        t=list;
                        do
            {
                        if(t.info==x)          /*node found*/
                                    break;
                        else
                                    t=t.right;
            }while(t!=null);
            if(t==null)
            {
                        System.out.println("\nElement not found");
                        return;
            }
            Nodetype q=new Nodetype(x);
            q.info=nx;
            r=t.right;
            if(r!=null)
                        r.left=q;
            q.right=r;
            q.left=t;
            t.right=q;
            display();
}                                   /*end insright*/

void delright(int x)
{
                                    /*delete a node which is towards right of a node*/
                       
Nodetype q,t;
                        t=list;
                        do
            {
                        if(t.info==x) /*node found*/
                                    break;
                       

else
                                    t=t.right;

            }           while(t!=null);
            if(t==null)
            {
                        System.out.println("\nElement not found");
                        return;
            }
            if(t.right==null)
            {
                        System.out.println("\nThere is no right node");
                        return;
            }
            q=t.right;
            System.out.println("\n\nThe deleted element is "+q.info);
            t.right=q.right;
            if(q.right!=null)

                        (q.right).left=t;
            display();
}                                   /*end delright*/

void insleft(int x,int nx)
{
                                    /*insert new node towards left of a specific node*/
            Nodetype l,t;

            t=list;
            do
            {
                        if(t.info==x)
                        break;
                        else
                        t=t.right;

            }           while(t!=null);
            if(t==null)
            {
                        System.out.println("\nElement not found");
                        return;
            }
            Nodetype q=new Nodetype(x);
            q.info=nx;
            l=t.left;
            if(l!=null)
            l.right=q;
            q.right=t;
            q.left=l;
            t.left=q;
            if(t==list)
            list=q;
            display();

}                       /*end insleft*/


void delleft(int x)
{
/*delete a node which is towards left of a specific node*/
            Nodetype l,q,t;
            t=list;
            do
            {
                        if(t.info==x)
                                    break;
                        else
                                    t=t.right;
            }

while(t!=null);
            if(t==null)
            {
                        System.out.println("\nElement not found");
                        return;
            }
            if(t.left==null)
            {
                        System.out.println("\nThere is no left node");
                        return;
            }
            q=t.left;
            if(q==list)
            list=t;
            System.out.println("\n\nThe deleted element is "+q.info);
           
t.left=q.left;
            l=q.left;
            if(l!=null)
                        (q.left).right=t;
            display();

}                                   /*end delleft*/

}

class LLDoubly
{
            public static void main(String args[])
            {
                        Operations L =new Operations();

                        System.out.print("\nInsert 55,50,40,90 in the begining ");
                        L.insertbeg(55);
                        L.insertbeg(50);
                        L.insertbeg(40);
                        L.insertbeg(90);

                        System.out.print("\n\nDelete 3 items from the beginning");
                        L.deletebeg();
                        L.deletebeg();
                        L.deletebeg();
                        System.out.print("\n\nInsert 11,22,33,44 in the end ");
                        L.insertend(11);
                        L.insertend(22);
                        L.insertend(33);
                        L.insertend(44);

                        System.out.print("\n\nDelete 2 items from the end");
                        L.deleteend();
                        L.deleteend();

                        System.out.print("\n\nInsert 100 to right of 11");
                        L.insright(11,100);

                        System.out.print("\n\nInsert 80 to left of 44");
                        L.insleft(44,80);

                        System.out.print("\n\nInsert 81 to left of 55");
                        L.insleft(55,81);

                        System.out.print("\n\nDelete item right of 100");
                        L.delright(100);

                        System.out.print("\n\nDelete item left of 22");
                        L.delleft(2);

                        System.out.print("\n\nDelete item left of 11");
                        L.delleft(11);
            }           /*end main*/
}



Output:

Insert 55,50,40,90 in the begining
List<==>|55|
List<==>|50|<==>|55|
List<==>|40|<==>|50|<==>|55|
List<==>|90|<==>|40|<==>|50|<==>|55|

Delete 3 items from the beginning
The deleted element is 90
List<==>|40|<==>|50|<==>|55|

The deleted element is 40
List<==>|50|<==>|55|
The deleted element is 50
List<==>|55|

Insert 11,22,33,44 in the end
List<==>|55|<==>|11|
List<==>|55|<==>|11|<==>|22|
List<==>|55|<==>|11|<==>|22|<==>|33|
List<==>|55|<==>|11|<==>|22|<==>|33|<==>|44|

Delete 2 items from the end
The deleted element is 44
List<==>|55|<==>|11|<==>|22|<==>|33|
The deleted element is 33
List<==>|55|<==>|11|<==>|22|

Insert 100 to right of 11
List<==>|55|<==>|11|<==>|100|<==>|22|
Insert 80 to left of 44
Element not found

Insert 81 to left of 55
List<==>|81|<==>|55|<==>|11|<==>|100|<==>|22|

Delete item right of 100
The deleted element is 22
List<==>|81|<==>|55|<==>|11|<==>|100|
Delete item left of 22
Element not found
Delete item left of 11
The deleted element is 55
List<==>|81|<==>|11|<==>|100|

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