Rotate List

Description

Given a linked list, rotate the list to the right by k places, where k is non-negative.

Example 1:

Input: 1->2->3->4->5->NULL, k = 2
Output: 4->5->1->2->3->NULL
Explanation:
rotate 1 steps to the right: 5->1->2->3->4->NULL
rotate 2 steps to the right: 4->5->1->2->3->NULL

Example 2:

Input: 0->1->2->NULL, k = 4
Output: 2->0->1->NULL
Explanation:
rotate 1 steps to the right: 2->0->1->NULL
rotate 2 steps to the right: 1->2->0->NULL
rotate 3 steps to the right: 0->1->2->NULL
rotate 4 steps to the right: 2->0->1->NULL

Solution(javascript)

const rotate = function (nums, k) {
  while (k > 0) {
    nums.unshift(nums.pop())
    k--
  }
  return nums
}

const rotateRight = function (head, k) {
  if (!head) {
    return head
  }
  const list = []
  let current = head
  while (current) {
    list.push(current)
    current = current.next
  }
  rotate(list, k % list.length)
    .forEach((node, index) => { node.next = list[index + 1] ? list[index + 1] : null })
  return list[0]
}