#1290 - Convert Binary Number in a Linked List to Integer

Easy • View on LeetCode • View on GitHub

Problem Description

Given `head` which is a reference node to a singly-linked list.

The value of each node in the linked list is either 0 or 1.

The linked list holds the binary representation of a number.

Return the decimal value of the number in the linked list.

Solution

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @return {number}
 */
var getDecimalValue = function(head) {
  let binary = String(head.val);

  while (head.next !== null) {
    head = head.next;
    binary += head.val;
  }

  return parseInt(binary, 2);
};