/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode rotateRight(ListNode head, int k) {
        if (k == 0 || head == null) return head;
        //获取链表长度
        ListNode tmp = head;
        int len = 0;
        while (tmp != null) {
            tmp = tmp.next;
            len++;
        }
        //如果k是len的整数倍，说明无须移动
        if (k % len == 0) return head;
        //链表分为A-B段,A段为 len - k % len B段为 k % len
        int aLen = len - k % len;
        int bLen = k % len - 1;
        ListNode nodeA = head, nodeB = new ListNode(-1);
        while (aLen-- > 1) {
            nodeA = nodeA.next;
        }
        //将A-B断开
        nodeB.next = nodeA.next;
        nodeA.next = null;

        //将B-A组装上
        tmp = nodeB.next;
        while(bLen-- > 0) {
            tmp = tmp.next;
        }
        tmp.next = head;
        return nodeB.next;
    }
}

复杂度分析：

• 时间复杂度：O(n)
• 空间复杂度：O(1)