Find length of Circular Linked List

Last Updated: 06 October, 2024 🕓 4 Mins

In this article, we will learn how to find the length of a circular linked list. Actually finding length means we will count the total number of nodes present in a linked list.

To count the node, we will traverse the linked list till the end node.

As we know that in a circular linked list, last node doesn't point to NULL instead it points to head; thus, we need to compare with the head pointer and traverse until the current node next is head.

For Example:

As given in the diagram, there are a total 3 nodes, so we can say that the length of a circular linked list is 3.

Example: Find the length of Circular Linked List in Java

  
  // Class representing a node in a circular linked list
  class Node {
    public int data;    // Store value of the node
    public Node next;   // Store address of the next node
  
    // Constructor to initialize a node
    public Node(int data) {
      this.data = data;
      this.next = null;
    }
  }
  
  // Java program to find the length of a circular linked list
  public class FindLenghInCLL {
    // Function to find length of circular linked list
    static void findLength(Node head) {
      int length = 0;
      if (head != null) {
        Node node = head;
        do {
          node = node.next;
          length++;
        } while (node != head);
      }
      System.out.println("Length of Circular Linked List is: " + length);
    }
  
    public static void main(String[] args) {
      // Create a circular linked list
      Node head = new Node(10);
      head.next = new Node(20);
      head.next.next = new Node(30);
      head.next.next.next = new Node(40);
      head.next.next.next.next = new Node(50);
      head.next.next.next.next.next = head;
  
      // Find and print the length of a Circular Linked List
      findLength(head);
    }
  }

Time Complexity: O(n), here n represent the total number of nodes in a circular linked list.