Write a C Program to implement double linked list operations

By | 26.03.2017

C Program to implement double linked list


Write a C Program to implement double linked list operations. Here’s simple Menu Driven C Program to implement double linked list operations like Creation, Insertion, Deletion, Display, Count, Add Node, Delete Node, Search, Reverse, etc.  in C Programming Language.


What is Linked List ?


Linked list is a linear data structure that contains sequence of elements such that each element links to its next element in the sequence. Each link contains a connection to another link.

Following are the important terms to understand the concept of Linked List.

  • Link − Each link of a linked list can store a data called an element.
  • Next − Each link of a linked list contains a link to the next link called Next.

Each element in a linked list is called as “Node”. Each node consists of its own data and the address of the next node and forms a chain. Linked Lists are used to create trees and graphs.


Basic Operations


Following are the basic operations supported by a list.

  • Insertion − Adds an element at the beginning of the list.
  • Deletion − Deletes an element at the beginning of the list.
  • Display − Displays the complete list.
  • Search − Searches an element using the given key.
  • Delete − Deletes an element using the given key.

Below is the source code for C Program to implement double linked list operations which is successfully compiled and run on Windows System to produce desired output as shown below :


SOURCE CODE : :


/* C C Program to implement double linked list operations */


#include<stdio.h>
#include<stdlib.h>

struct node
{
        struct node *prev;
        int info;
        struct node *next;
};

struct node *create_list(struct node *start);
void display(struct node *start);
struct node *addtoempty(struct node *start,int data);
struct node *addatbeg(struct node *start,int data);
struct node *addatend(struct node *start,int data);
struct node *addafter(struct node *start,int data,int item);
struct node *addbefore(struct node *start,int data,int item);
struct node *del(struct node *start,int data);
struct node *reverse(struct node *start);

int main()
{
        int choice,data,item;
        struct node *start=NULL;
        while(1)
        {
                printf("\n\n1.Create List\n");
                printf("2.Display\n");
                printf("3.Add to empty list\n");
                printf("4.Add at beginning\n");
                printf("5.Add at end\n");
                printf("6.Add after\n");
                printf("7.Add before\n");
                printf("8.Delete\n");
                printf("9.Reverse\n");
                printf("10.Quit\n");
                printf("\nEnter your choice : ");
                scanf("%d",&choice);
                switch(choice)
                {
                 case 1:
                        start=create_list(start);
                        break;
                 case 2:
                        display(start);
                        break;
                 case 3:
                        printf("Enter the element to be inserted : ");
                        scanf("%d",&data);
                        start=addtoempty(start,data);
                        break;
                 case 4:
                printf("Enter the element to be inserted : ");
                        scanf("%d",&data);
                        start=addatbeg(start,data);
                        break;
                 case 5:
                        printf("Enter the element to be inserted : ");
                        scanf("%d",&data);
                        start=addatend(start,data);
                        break;
                 case 6:
                        printf("Enter the element to be inserted : ");
                        scanf("%d",&data);
                        printf("Enter the element after which to insert : ");
                        scanf("%d",&item);
                        start=addafter(start,data,item);
                        break;
                 case 7:
                        printf("Enter the element to be inserted : ");
                        scanf("%d",&data);
                        printf("Enter the element before which to insert : ");
                        scanf("%d",&item);
                        start=addbefore(start,data,item);
                        break;
                 case 8:
                        printf("Enter the element to be deleted : ");
                        scanf("%d",&data);
                        start=del(start,data);
                        break;
                 case 9:
                        start=reverse(start);
                        break;
                 case 10:
                        exit(1);
                 default:
                        printf("Wrong choice\n");
        }/*End of switch*/
   }/*End of while*/

   return 0;

}/*End of main()*/

struct node *create_list(struct node *start)
{
        int i,n,data;
        printf("\nEnter the number of nodes : ");
        scanf("%d",&n);
        start=NULL;
        if(n==0)
                return start;
        printf("Enter the element to be inserted : ");
        scanf("%d",&data);
        start=addtoempty(start,data);

        for(i=2;i<=n;i++)
        {
                printf("Enter the element to be inserted : ");
                scanf("%d",&data);
                start=addatend(start,data);
        }
        return start;
}/*End of create_list()*/

void display(struct node *start)
{
        struct node *p;
        if(start==NULL)
        {
                printf("\nList is empty\n");
                return;
        }
        p=start;
        printf("\nList is :\n");
        while(p!=NULL)
        {
                printf("%d ",p->info);
                p=p->next;
        }
        printf("\n");
}/*End of display() */

struct node *addtoempty(struct node *start,int data)
{
        struct node *tmp;
        tmp=(struct node *)malloc(sizeof(struct node));
        tmp->info=data;
        tmp->prev=NULL;
        tmp->next=NULL;
        start=tmp;
        return start;
}/*End of addtoempty( )*/

struct node *addatbeg(struct node *start,int data)
{
        struct node *tmp;
        tmp = (struct node *)malloc(sizeof(struct node));
        tmp->info=data;
        tmp->prev=NULL;
        tmp->next=start;
        start->prev=tmp;
        start=tmp;
        return start;
}/*End of addatbeg( )*/

struct node *addatend(struct node *start,int data)
{
        struct node *tmp,*p;
        tmp=(struct node *)malloc(sizeof(struct node));
        tmp->info=data;
        p=start;
        while(p->next!=NULL)
                p=p->next;
        p->next=tmp;
        tmp->next=NULL;
        tmp->prev=p;
        return start;
}/*End of addatend( )*/

struct node *addafter(struct node *start,int data,int item)
{
        struct node *tmp,*p;
        tmp=(struct node *)malloc(sizeof(struct node));
        tmp->info=data;
        p=start;
        while(p!=NULL)
        {
                if(p->info==item)
                {
                        tmp->prev=p;
                        tmp->next=p->next;
                        if(p->next!=NULL)
                                p->next->prev=tmp;
                        p->next=tmp;
                        return start;
                }
                p=p->next;
        }
        printf("\n%d not present in the list\n\n",item);
        return start;
}/*End of addafter()*/

struct node *addbefore(struct node *start,int data,int item)
{
        struct node *tmp,*q;
        if(start==NULL )
        {
                printf("\nList is empty\n");
                return start;
        }
        if(start->info==item)
        {
                tmp = (struct node *)malloc(sizeof(struct node));
                tmp->info=data;
                tmp->prev=NULL;
                tmp->next=start;
                start->prev=tmp;
                start=tmp;
                return start;
        }
        q=start;
        while(q!=NULL)
        {
                if(q->info==item)
                {
                        tmp=(struct node *)malloc(sizeof(struct node));
                        tmp->info=data;
                        tmp->prev=q->prev;
                        tmp->next = q;
                        q->prev->next=tmp;
                        q->prev=tmp;
                        return start;
                }
                q=q->next;
        }
        printf("\n%d not present in the list\n",item);
        return start;
}/*End of addbefore()*/

struct node *del(struct node *start,int data)
{
        struct node *tmp;
        if(start==NULL)
        {
                printf("\nList is empty\n");
                return start;
        }
        if(start->next==NULL)        /*only one node in the list*/
                if(start->info==data)
                {
                        tmp=start;
                        start=NULL;
                        free(tmp);
                        return start;
                }
                else
                {
                        printf("\nElement %d not found\n",data);
                        return start;
                }
        /*Deletion of first node*/
        if(start->info==data)
        {
                tmp=start;
                start=start->next;
                start->prev=NULL;
                free(tmp);
                return start;
        }
        /*Deletion in between*/
        tmp=start->next;
        while(tmp->next!=NULL )
        {
                if(tmp->info==data)
                {
                        tmp->prev->next=tmp->next;
                        tmp->next->prev=tmp->prev;
                        free(tmp);
                        return start;
                }
                tmp=tmp->next;
        }
        /*Deletion of last node*/
        if(tmp->info==data)
        {
                tmp->prev->next=NULL;
                free(tmp);
                return start;
        }
        printf("\nElement %d not found\n",data);
        return start;
}/*End of del()*/

struct node *reverse(struct node *start)
{
        struct node *p1,*p2;
        p1=start;
        p2=p1->next;
        p1->next=NULL;
        p1->prev=p2;
        while(p2!=NULL)
        {
                p2->prev=p2->next;
                p2->next=p1;
                p1=p2;
                p2=p2->prev;
        }
        start=p1;
        printf("\nList reversed\n");
        return start;
}/*End of reverse()*/

OUTPUT  : :


*************** OUTPUT ***************


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 1

Enter the number of nodes : 4
Enter the element to be inserted : 1
Enter the element to be inserted : 2
Enter the element to be inserted : 3
Enter the element to be inserted : 4


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 2

List is :
1 2 3 4


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 3
Enter the element to be inserted : 5


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 2

List is :
5


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 4
Enter the element to be inserted : 3


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 2

List is :
3 5


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 5
Enter the element to be inserted : 6


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 6
Enter the element to be inserted : 4
Enter the element after which to insert : 3


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 7
Enter the element to be inserted : 2
Enter the element before which to insert : 3


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 2

List is :
2 3 4 5 6


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 8
Enter the element to be deleted : 6


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 9

List reversed


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 2

List is :
5 4 3 2


1.Create List
2.Display
3.Add to empty list
4.Add at beginning
5.Add at end
6.Add after
7.Add before
8.Delete
9.Reverse
10.Quit

Enter your choice : 10

If you found any error or any queries related to the above program or any questions or reviews , you wanna to ask from us ,you may Contact Us through our contact Page or you can also comment below in the comment section.We will try our best to reach upto you in the short interval.


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