#3294 - Convert Doubly Linked List to Array II

Medium • View on LeetCode • View on GitHub

Problem Description

You are given an arbitrary node from a doubly linked list, which contains nodes that have a next pointer and a previous pointer.

Return an integer array which contains the elements of the linked list in order.

Solution

/**
 * // Definition for a _Node.
 * function _Node(val,prev,next) {
 *    this.val = val;
 *    this.prev = prev;
 *    this.next = next;
 * };
 */
/**
 * @param {_Node} node
 * @return {number[]}
 */
var toArray = function(node) {
  const result = [];
  let headNode = node;

  while (headNode.prev) {
    headNode = headNode.prev;
  }

  let currentNode = headNode;
  while (currentNode) {
    result.push(currentNode.val);
    currentNode = currentNode.next;
  }

  return result;
};