C program to create a doubly linked list with insert front, insert rear, delete front,delete rear, display functions;
PROGRAM:
#include <stdio.h>#include <stdlib.h>
struct node
{
int data;
struct node *rlink;
struct node *llink;
}*first=NULL;
void insert_front()
{
struct node *new_node;
new_node=(struct node *)malloc(sizeof(struct node));
printf("Enter an element\n");
scanf("%d",&new_node->data);
new_node->llink=NULL;
new_node->rlink=NULL;
if(first==NULL)
{
first=new_node;
}
else
{
new_node->rlink=first;
first->llink=new_node;
first=new_node;
}
}
void insert_rear()
{
struct node *new_node,*temp;
new_node=(struct node *)malloc(sizeof(struct node));
printf("Enter an element\n");
scanf("%d",&new_node->data);
new_node->rlink=NULL;
new_node->llink=NULL;
if(first==NULL)
{
first=new_node;
}
else
{
temp=first;
while(temp->rlink!=NULL)
{
temp=temp->rlink;
}
temp->rlink=new_node;
new_node->llink=temp;
}
}
void delet_front()
{
struct node *x;
if(first==NULL)
printf("Deletion not possible, linked list empty!\n");
else if(first->rlink==NULL)
{
printf("Element deleted is %d\n",first->data);
free(first);
first=NULL;
}
else
{
printf("Element deleted is %d\n",first->data);
x=first;
first=first->rlink;
free(x);
x=NULL;
}
}
void delet_rear()
{
struct node *temp;
if(first==NULL)
{
printf("Delete not possible, linked list empty!\n");
}
else if(first->rlink==NULL)
{
printf("Element deleted is %d",first->data);
free(first);
first=NULL;
}
else
{
temp=first;
while(temp->rlink->rlink!=NULL)
{
temp=temp->rlink;
}
printf("Element deleted is %d",temp->rlink->data);
free(temp->rlink);
temp->rlink=NULL;
}
}
void disp()
{
struct node *temp;
if(first==NULL)
{
printf("Display not possible, linked list empty!\n");
}
else if(first->rlink==NULL)
{
printf("Displaying data in the linked list:\n %d\n",first->data);
}
else
{
temp=first;
printf("Displaying data in the linked list:\n");
while(temp!=NULL)
{
printf("%d\t",temp->data);
temp=temp->rlink;
}
printf("\n");
}
}
int main()
{
int choice;
while(1)
{
printf("\nEnter your choice\n");
printf("1 to insert front\n");
printf("2 to insert rear\n");
printf("3 to delete front\n");
printf("4 to delete rear\n");
printf("5 to display linked list\n");
printf("0 to exit\n");
printf("\nEnter your choice:");
scanf("%d",&choice);
switch(choice)
{
case 1:insert_front();
break;
case 2:insert_rear();
break;
case 3:delet_front();
break;
case 4:delet_rear();
break;
case 5:disp();
break;
case 0: return 0;
break;
default:printf("Invalid Entry!\n");
}
}
return 0;
}
OUTPUT:
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:6
Invalid Entry!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Display not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:3
Deletion not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:4
Delete not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:1
Enter an element
10
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
10
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:1
Enter an element
20
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:1
Enter an element
30
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
30 20 10
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:2
Enter an element
40
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:2
Enter an element
50
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
30 20 10 40 50
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:3
Element deleted is 30
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
20 10 40 50
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:4
Element deleted is 50
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
20 10 40
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:3
Element deleted is 20
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:4
Element deleted is 40
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Displaying data in the linked list:
10
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:3
Element deleted is 10
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:5
Display not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:3
Deletion not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:4
Delete not possible, linked list empty!
Enter your choice
1 to insert front
2 to insert rear
3 to delete front
4 to delete rear
5 to display linked list
0 to exit
Enter your choice:0