/***************************
 author-Nikunj v Gandhi
 from-gujarat(surat)
 Web Developer(ZCE)
 email-nik_gandhi007@yahoo.com
 http://my-source-codes.blogspot.com/
 Description:Doubly linked list using c program
 ******************************************** */
 #include<conio.h>
 #include<stdio.h>
 #include<malloc.h>
 struct link
 {
 int data;
 struct link *next;
 struct link *prev;
 }*start,*trav,*temp,*lright,*lleft,*t;
 void create()
 {
 int k=1,i=0;
 while(k==1)
 {
 temp=malloc(sizeof(struct link *));
 if(temp==NULL)
 {
 printf("NOT ENOUGH MEMORY TO CREATE NODEnn");
 exit();
 }
 printf("Enter data?");
 scanf("%d",&temp->data);
 temp->next=NULL;
 temp->prev=NULL;
 if(start==NULL)
 {
 start=temp;
 lleft=temp;
 lright=temp;
 trav=start;
 }
 else
 {
 lright->next=temp;
 lright=lright->next;
 if(i==0)
 {
 lleft->prev=NULL;
 i=1;
 }
 else
 {
 trav=trav->next;
 lleft->prev=trav;
 lleft=lleft->prev;
 }
 }
 printf("enter 1 for insert again?");
 scanf("%d",&k);
 }
 }
 void display()
 {
 trav=start;
 while(trav!=NULL)
 trav=trav->next;
 t=trav;
 while(t!=NULL)
 {
 printf("%dn",t->data);
 t=t->prev;
 }
 }
 void main()
 {
 int d,w=0;
 clrscr();
 while(w!=3)
 {
 printf("1 CREATE DOUBLY LIKED LISTn2 DISPLAYn3 EXITn");
 printf("Enter your choice?");
 scanf("%d",&w);
 if(w==1)
 create();
 else if(w==2)
 display();
 else if(w==3)
 exit();
 }
 }