Circular Linked List Java

PROGRAM TO CHECK IF A LINKED LIST IS CIRCULAR LINKED LIST

import java.util.*;

  

class GFG

{

      

/* Link list Node */

static class Node

{

    int data;

    Node next;

}

  

/*This function returns true if given linked

list is circular, else false. */

static boolean isCircular( Node head)

{

    // An empty linked list is circular

    if (head == null)

    return true;

  

    // Next of head

    Node node = head.next;

  

    // This loop would stop in both cases (1) If

    // Circular (2) Not circular

    while (node != null && node != head)

    node = node.next;

  

    // If loop stopped because of circular

    // condition

    return (node == head);

}

  

// Utility function to create a new node.

static Node newNode(int data)

{

    Node temp = new Node();

    temp.data = data;

    temp.next = null;

    return temp;

}

  

/* Driver code*/

public static void main(String args[])

{

    /* Start with the empty list */

    Node head = newNode(1);

    head.next = newNode(2);

    head.next.next = newNode(3);

    head.next.next.next = newNode(4);

  

    System.out.print(isCircular(head)? "Yes\n" :

                    "No\n" );

  

    // Making linked list circular

    head.next.next.next.next = head;

  

    System.out.print(isCircular(head)? "Yes\n" :

                    "No\n" );

  

}

}




OUTPUT

No
Yes

CREDITS: https://www.geeksforgeeks.org/check-if-a-linked-list-is-circular-linked-list/