rotatelinkedlist.js

class Node {
  constructor(data, next = null) {
    this.data = data;
    this.next = next;
  }
}

class LinkedList {
  constructor() {
    this.head = null;
  }

  rotate(k) {
    if (!this.head) {
      return null;
    }

    let current = this.head;
    let length = 1;

    // Traverse the linked list to find its length and the last node
    while (current.next) {
      current = current.next;
      length++;
    }

    // Set the next node of the last node to the current head node
    current.next = this.head;

    // Find the new head node by moving k nodes from the current head node
    let newHeadIndex = length - k % length;
    current = this.head;
    let i = 0;
    while (i < newHeadIndex - 1) {
      current = current.next;
      i++;
    }

    // Set the next node of the node at position k-1 to null
    this.head = current.next;
    current.next = null;

    // Return the new head node
    return this.head;
  }
}

// Example usage
const list = new LinkedList();
list.head = new Node(1);
list.head.next = new Node(2);
list.head.next.next = new Node(3);
list.head.next.next.next = new Node(4);
list.head.next.next.next.next = new Node(5);

list.rotate(2); // Output: Node { data: 4, next: Node { data: 5, next: Node { data: 1, next: Node { data: 2, next: Node { data: 3, next: null } } } } }