Code for implementing Circular Linked List and its operations.
This code is designed to implement all the operations of circular linked list. In this code a circular linked list created and then one by one several operations are added. The operations available in this code are create(), insertatfirst(), insertatend(), inserafter(), insertbefore(), deletenode() and display().
All these operations are implemented using same name method as mentioned above.
All method or functions are written in easy language for understanding circular linked list as much easy as possible.
For Such more codes click here and for video tutorial click here.
// OPERATIONS OF CIRCULAR LINKED LIST
#include <stdio.h>
#include <stdlib.h>
typedef struct node
{
int data;
struct node *next;
} clrlnk;
clrlnk *create();
void display(clrlnk *);
clrlnk*insertatfirst(clrlnk*,int);
void insertatend(clrlnk *,int);
void insertafter(clrlnk *,int,int);
clrlnk *insertbefore(clrlnk *,int,int);
clrlnk* deletenode(clrlnk *,int);
void main()
{
clrlnk *head=NULL;
int val,gval;
int ch;
while(1)
{
printf("\n1)create\n2)insert at first\n3)insert at end\n4)insert after a node\n5)insert before a node\n6)Delete a node\n7)Display");
printf("\nEnter your choice:");
scanf("%d",&ch);
switch(ch)
{
case 1:
head=create();
break;
case 2:
printf("\nEnter the value:");
scanf("%d",&val);
head=insertatfirst(head,val);
break;
case 3:
printf("\nEnter the value:");
scanf("%d",&val);
insertatend(head,val);
break;
case 4:
printf("\nEnter the value you want to add:");
scanf("%d",&val);
printf("\nEnter the value after which you want to add:");
scanf("%d",&gval);
insertafter(head,val,gval);
break;
case 5:
printf("\nEnter the value you want to add:");
scanf("%d",&val);
printf("\nEnter the value before which you want to add:");
scanf("%d",&gval);
head=insertbefore(head,val,gval);
break;
case 6:
printf("\nEnter the value you want to delete: ");
scanf("%d",&val);
head=deletenode(head,val);
break;
case 7:
printf("\nLinked list is:");
display(head);
break;
}
}
}
clrlnk *create()
{
clrlnk *head=NULL;
clrlnk *ptr;
int val;
while (1)
{
printf("\nEnter the data(enter any negative value for exit ):");
scanf("%d", &val);
if (val < 0)
{
return head;
}
clrlnk *new = (clrlnk *)malloc(sizeof(clrlnk));
new->data = val;
new->next = NULL;
if (head == NULL)
{
head = new;
}
else
{
ptr->next = new;
}
ptr = new;
ptr->next = head;
}
}
clrlnk*insertatfirst(clrlnk*head,int val)
{
clrlnk *ptr;
clrlnk *q=head;
ptr=(clrlnk*)malloc(sizeof(clrlnk));
while(q->next!=head)
{
q=q->next;
}
ptr->data=val;
q->next=ptr;
ptr->next=head;
head=ptr;
return head;
}
void insertatend(clrlnk*head,int val)
{
clrlnk *ptr;
clrlnk *q=head->next;
ptr=(clrlnk*)malloc(sizeof(clrlnk));
while(q->next!=head)
{
q=q->next;
}
ptr->data=val;
ptr->next=q->next;
q->next=ptr;
}
void insertafter(clrlnk*head,int val,int gval)
{
clrlnk *ptr;
clrlnk *q=head;
ptr=(clrlnk*)malloc(sizeof(clrlnk));
while(q->data!=gval && q->next!=head)
{
q=q->next;
}
ptr->data=val;
ptr->next=q->next;
q->next=ptr;
}
clrlnk* insertbefore(clrlnk*head,int val,int gval)
{
clrlnk *ptr,*pre,*h;
clrlnk *q;
if(head->data==gval)
{
h=insertatfirst(head,val);
return h;
}
else
{
q=head->next;
ptr=(clrlnk*)malloc(sizeof(clrlnk));
while(q->data!=gval && q!=head)
{
pre=q;
q=q->next;
}
ptr->data=val;
ptr->next=pre->next;
pre->next=ptr;
return head;
}
}
clrlnk *deletenode(clrlnk *h,int v)
{
clrlnk *ptr,*pre;
if(h->data==v)
{
ptr=h;
while(ptr->next!=h)
ptr=ptr->next;
h=h->next;
ptr->next=h;
}
else
{
pre=h;
ptr=h->next;
while(ptr->data!=v && ptr!=h)
{
pre=ptr;
ptr=ptr->next;
}
if(ptr!=h)
pre->next=ptr->next;
else
printf("Value not found");
}
return h;
}
void display(clrlnk *head)
{
clrlnk *p = head;
do {
printf("%d ", p->data);
p = p->next;
}
while (p!= head);
}
