Concatenate Two Circular Linked Lists

/*
Write a program to concatenate two circular linked lists.
*/

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

struct node
{
    int info;
    struct node *link;
};

struct node *create_list(struct node *last);
void display(struct node *last);
struct node *addtoempty(struct node *last,int data );
struct node *addatend(struct node *last,int data);
struct node *concat(struct node *last1,struct node *last2);

main( )
{
    struct node *last1=NULL,*last2=NULL;
    last1=create_list(last1);
    last2=create_list(last2);
    printf("First list is :  ");
    display(last1);
    printf("Second list is :  ");
    display(last2);
    last1=concat(last1, last2);
    printf("Concatenated list is  : ");
    display(last1);
}

struct node *concat( struct node *last1,struct node *last2)
{
    struct node *ptr;
    if(last1==NULL)
    {
        last1=last2;
        return last1;
    }
    if(last2==NULL )  
        return last1;
    ptr=last1->link;
    last1->link=last2->link;
    last2->link=ptr;
    last1=last2;
    return last1;
}
struct node *create_list(struct node *last)
{
    int i,n;
    int data;
    printf("Enter the number of nodes : ");
    scanf("%d",&n);
    last=NULL;
    if(n==0)
        return last;
    printf("Enter the element to be inserted : ");
    scanf("%d",&data);
    last=addtoempty(last,data);
       
    for(i=2;i<=n;i++)
    {
        printf("Enter the element to be inserted : ");
        scanf("%d",&data);
        last=addatend(last,data);   
    }
    return last;
}

void display(struct node *last)
{
    struct node *p;
    if(last==NULL)
    {
        printf("List is empty\n");
        return;
    }
    p=last->link;  /*p points to first node*/
    do
    {
        printf("%d ", p->info);
        p=p->link;
    }while(p!=last->link);
    printf("\n");
}

struct node *addtoempty(struct node *last,int data)
{
    struct node *tmp;
    tmp = (struct node *)malloc(sizeof(struct node));
    tmp->info = data;
    last = tmp;
    last->link = last;
    return last;
}

struct node *addatend(struct node *last,int data)
{
    struct node *tmp;
    tmp = (struct node *)malloc(sizeof(struct node));
    tmp->info = data;
    tmp->link = last->link;
    last->link = tmp;
    last = tmp;
    return last;
}




Related Posts,

 1. Circular Linked List    

 2. Concatenate Two Circular Linked Lists 

 3. Queue using Circular Linked List  

 4. Dequeue using Circular Array

 5. Circular Queue  

Please follow our blog as well as Share with your friends.

One of the best blog on the WWW for C Programmers. This blog contains more than 1,000+  C Programs written by programmers and verified by experts. 

If you want to share your programming skill with us then write email on sdk852018@gmail.com for Guest Post, We will publish your post after verified by our expert team.

Thanks in Advance !!! Enjoy Programming ...!!!