circularlinked.c

#include <stdio.h>
#include <stdlib.h>
struct node {
    int data ;
    struct node * next;
};
void traversal(struct node *head){
    struct node *ptr = head;
    do{
        printf("Element %d \n", ptr-> data);
        ptr = ptr ->next;
    }while(ptr !=head);
    }
struct node*deletefirstelement(struct node*head){
    struct node*q= head;
    struct node *p = head->next;
    while (p->next != head){
        p= p->next;
    }
    p->next = q->next;
    head = q->next;
    free(q);
    return head;
}
struct node* insertfirst(struct node* head, int data){
    struct node*ptr = (struct node*) malloc(sizeof(struct node));
    struct node *p = head ->next;
    ptr ->data = data;
    while (p->next != head){
        p=p->next;
    }
    p->next = ptr;
    ptr -> next = head;
    head = ptr;
    return head;

}
struct node* insertindex(struct node*head , int data , int postion){
    struct node *ptr = (struct node* )malloc(sizeof(struct node));
    struct node *p = head;
    ptr -> data = data;
    int i =0;
    while (i != postion-1){
        p=p->next;
        i++;
    }
    ptr -> next = p->next;
    p-> next = ptr;
    return head;
}
int main (){
    struct node *head ;
    struct node *second;
    struct node * third; 
    struct node * fourth ;
    head = (struct node *)malloc (sizeof(struct node));
    second = (struct node*)malloc(sizeof(struct node));
    third = (struct node *)malloc(sizeof(struct node));
    fourth = (struct node*)malloc (sizeof(struct node));
    head -> data = 32;
    head -> next = second;
    second -> data = 72;
    second -> next = third;
    third -> data = 992;
    third -> next = fourth;
    fourth -> data = 320;
    fourth -> next = head;
    traversal(head);
    printf(" \n");
    head = insertfirst(head, 54);
    head = insertfirst(head, 77);
    traversal(head);
    printf(" \n");
    insertindex(head , 45 , 4);
    traversal (head);
    printf(" \n");
    head = deletefirstelement(head);
    traversal(head);
    return 0;
}