2807.js

/** ------------------------------------------------------------------------------
 * 
 * 2807. Insert Greatest Common Divisors in Linked List
 * Topics: Linked List
 * https://leetcode.com/problems/insert-greatest-common-divisors-in-linked-list/description/
 * 
 ------------------------------------------------------------------------------ */
/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var insertGreatestCommonDivisors = function (head) {
  let cur = head

  const gcd = (n, m) => {
    while (m !== 0) {
      const remainder = n % m
      n = m
      m = remainder
    }
    return n
  }

  while (cur.next) {
    const value = gcd(cur.val, cur.next.val)
    const newNode = {
      val: value,
      next: cur.next,
    }
    cur.next = newNode
    cur = newNode.next
  }

  return head
}