This document describes a C program that implements a double linked list. It includes functions to insert, delete, search, and display nodes in the list. The insert function allocates a new node, gets the insertion position and data from the user, and adds the new node to the list by updating the next and prev pointers of neighboring nodes. It checks for special cases like insertion at the head or end of the list. The other functions are not described in detail.

1. Double Linked List
#include<stdio.h>
#include<conio.h>
#include<process.h>
#include<alloc.h>
struct node
{
int data;
struct node *prev,*next;
}*start=NULL,*p,*q, *r, *New;
int item, pos, c=0, i;

2. Double Linked List
void main()
{
int ch;
clrscr();
do
{
printf("n***MENU***");
printf("n1.Insertn2.Deleten3.Searchn4.Displayn5.Exit");
printf("nPlease Enter the choice...");
scanf("%d",&ch); 1
switch(ch)
{
case 1:insert();break;
case 2:del();break;
case 3:search();break;
case 4:disp();break;
case 5:exit(0);
default:printf("nInvalid Choice...n");
}
}while(ch!=5);
getch();
}

3. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); 1 for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
New

4. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); 10 c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
New 10

5. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
New 10

6. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start = NULL
New 10

7. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start = NULL
New 10

8. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
c=0+1
New,
10
start

9. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("Data Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("n Invalid Position...n");
c++;
}
}
c=0+1
New,
10
start

10. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); 2 for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 New

11. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); 20 c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 New 20

12. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 New 20

13. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 New 20
p

14. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 New 20
p

15. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
q = NULL
start 10 New 20
p

16. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
q = NULL
start 10 New 20
p

17. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
q = NULL
start 10 New 20
p

18. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("Data Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
q = NULL
start 10 New 20
p

19. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); 2 for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
New 15

20. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); 15 c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
New 15

21. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
New 15

22. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
P
New 15

23. void insert() else
{ {
printf("nEnter the position where to insert..."); p=start;
scanf("%d",&pos); for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node)); p=p->next;
New->prev=New->next=NULL; q = p->next;
if(pos<=c+1) New->next=q; New->prev=p;
{ p->next=New;
printf("nEnter the data to be inserted..."); q->prev=New;
scanf("%d",&New->data); c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
P
New 15

24. void insert()
else
{
{
printf("nEnter the position where to insert...");
p=start;
scanf("%d",&pos);
for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node));
p=p->next;
New->prev=New->next=NULL;
q = p->next;
if(pos<=c+1)
New->next=q; New->prev=p;
{
p->next=New;
printf("nEnter the data to be inserted...");
q->prev=New;
scanf("%d",&New->data);
c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
p q
New 15

25. void insert()
else
{
{
printf("nEnter the position where to insert...");
p=start;
scanf("%d",&pos);
for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node));
p=p->next;
New->prev=New->next=NULL;
q = p->next;
if(pos<=c+1)
New->next=q; New->prev=p;
{
p->next=New;
printf("nEnter the data to be inserted...");
q->prev=New;
scanf("%d",&New->data);
c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
p q
New 15

26. void insert()
else
{
{
printf("nEnter the position where to insert...");
p=start;
scanf("%d",&pos);
for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node));
p=p->next;
New->prev=New->next=NULL;
q = p->next;
if(pos<=c+1)
New->next=q; New->prev=p;
{
p->next=New;
printf("nEnter the data to be inserted...");
q->prev=New;
scanf("%d",&New->data);
c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
p q
New 15

27. void insert()
else
{
{
printf("nEnter the position where to insert...");
p=start;
scanf("%d",&pos);
for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node));
p=p->next;
New->prev=New->next=NULL;
q = p->next;
if(pos<=c+1)
New->next=q; New->prev=p;
{
p->next=New;
printf("nEnter the data to be inserted...");
q->prev=New;
scanf("%d",&New->data);
c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
p q
New 15

28. void insert()
else
{
{
printf("nEnter the position where to insert...");
p=start;
scanf("%d",&pos);
for(i=1;i<pos-1;i++)
New=(struct node *)malloc(sizeof(struct node));
p=p->next;
New->prev=New->next=NULL;
q = p->next;
if(pos<=c+1)
New->next=q; New->prev=p;
{
p->next=New;
printf("nEnter the data to be inserted...");
q->prev=New;
scanf("%d",&New->data);
c++;
if(pos==1)
}
{
printf("nData Inserted Successfully );
New->next=start;
}
start->prev=New;
else
start=New;
printf("nInvalid Position...n");
c++;
}
}
start 10 20
p q
New 15

29. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20

30. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); 15 r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20

31. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

32. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

33. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

34. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

35. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

36. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p

37. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
p q

38. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
r p q

39. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
r p q

40. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 15 20
r p q

41. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20

42. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); 10 r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20

43. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20
p

44. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20
p

45. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20
p

46. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
start 10 20
p

47. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
10 20
p start

48. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
10 20
p start

49. void del() if(p->prev==NULL)
{ {
if(start==NULL) start=start->next;
{ start->prev=NULL;
printf("nList is Empty...n"); }
return; else
} {
printf("nEnter the Data to be Deleted...n"); q = p->next;
scanf("%d",&item); r = p->prev;
p=start; r->next = q;
while(p!=NULL&&p->data!=item) q->prev = r;
p=p->next; }
if(p==NULL) c--;
{ printf("%d is Deleted...n",p->data);
printf("nData is not found...n"); free(p);
return;
}
}
20
start

50. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20

51. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); 15 if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20

52. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

53. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

54. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

55. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

56. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

57. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found...n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p

58. void search() while(p!=NULL)
{ {
if(start==NULL) if(item==p->data)
{ {
printf("nList is Empty...n"); printf("Data is Found.n");
return; break;
} }
printf("nEnter the Item to be p=p->next;
Searched..."); }
scanf("%d",&item); if(p==NULL)
p=start; printf("nData is not Found...n");
}
start 10 15 20
p