Search a in Circular Linked List

Search a specific node in Circular Linked List

Last Updated: 06 October, 2024 🕓 5 Mins

Searching for a specific node in a circular linked list can be done by traversing the list starting from the head node. We will continue moving to the next node until we either find the target node or return to the head, indicating that the node is not present in the list.

In this tutorial, we will understand how to search for a specific node in a circular linked list with a given Java program.

Example:

Java program to find a node in a circular linked list

  
  // Java program to search for a value in a circular linked list
  
  public class SearchinCLL {
    // Function to search a specific value
    static void search(Node last, int key) {
      // Returns, if the list is empty
      if (last == null) {
        System.out.println("List is an empty.");
        return;
      }
      
      Node head = last.next;
      Node curr = head;
      
      // Traverse the list to find the key
      while (curr != last) {
        if (curr.data == key) {
          // Key found
          System.out.println("The key: " + key + " is found.");
          return;
        }
        curr = curr.next;
      }
      
      // Check the last node
      if (last.data == key) {
        // Key found
        System.out.println("The key: " + key + " is found.");
        return;
      }
      // Key not found
      System.out.println("The key: " + key + " is not found.");
    }
    
    // Print list
    static void printList(Node last) {
      if (last == null)
        return;
      
      Node head = last.next;
      while (true) {
        System.out.print(head.data + " ");
        head = head.next;
        if (head == last.next)
          break;
      }
      System.out.println();
    }
    
    public static void main(String[] args) {
      // Create a circular linked list
      Node head = new Node(50);
      head.next = new Node(20);
      head.next.next = new Node(40);
      head.next.next.next = new Node(10);
      head.next.next.next.next = new Node(30);
      head.next.next.next.next.next = head;
      
      System.out.print("List value: ");
      printList(head);
      
      // Passing null as a node and 40 as a key
      search(null, 40);
      
      // Passing 40 as a key which is present in the list
      search(head, 40);
      
      // Passing 90 as a key which is not present in the list
      search(head, 90);
    }
  }