1
var rotateRight = function (head, k) {
2
  if (k === 0 || !head) return head;
3

4
  let n = 0;
5
  let end = null;
6

7
  let iterator = head;
8
  while (iterator) {
9
    n += 1;
10
    end = iterator;
11
    iterator = iterator.next;
12
  }
13

14
  const nodesToRotate = k % n;
15
  if (nodesToRotate === 0) return head;
16

17
  let breakAt = n - nodesToRotate;
18
  iterator = head;
19
  while (breakAt - 1 > 0) {
20
    iterator = iterator.next;
21
    breakAt -= 1;
22
  }
23

24
  const newHead = iterator.next;
25
  iterator.next = null;
26
  end.next = head;
27

28
  return newHead;
29
};