LeetCode brush problem, rotation list (61)

Rotating list

Given a linked list, move each node of the list k bits to the right.

The problem solving code

Find the end node of the linked list, string the list into a loop, and move k nodes in turn

var rotateRight = function(head, k) {
  if(! head)return null;
  let n = 1; // Record the length of the list
  let p = head; // Record the header
  while (p.next) {
    p = p.next;
    n += 1;
  }
  p.next = head; // join the top node to become a circular list
  k %= n; // If k is large, it will loop a lot. This time directly with the drop list length.
  k = n - k; // Subtract k from the final number of steps.
  while (k--) p = p.next; // Move the k bit list
  head = p.next; // After the move, assign the loop's linked list to the header
  p.next = null; // Break the last node of the circular list, that is, the list after moving k bits
  return head;
};
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