LeetCoding Challenge Oct. 7: Rotate List

문제의 개요

생각

코드

class Solution {
    public ListNode rotateRight(ListNode head, int k) {
        if (head == null || head.next == null) {
            return head;
        }

        ListNode tail = null;
        int len = 0;
        for (ListNode node = head; node != null; node = node.next) {
            tail = node;
            len++;
        }

        k = len - (k % len);
        if (k == 0) {
            return head;
        }

        tail.next = head;

        for (ListNode node = head; k > 0; node = node.next) {
            tail = node;
            k--;
        }

        head = tail.next;
        tail.next = null;

        return head;
    }
}