leetcode 面试题 02.02. 返回倒数第 k 个节点

题目 双指针：

class Solution { public int kthToLast(ListNode head, int k) { ListNode dummy=new ListNode(-1); dummy.next=head; ListNode quick=dummy; ListNode slow=dummy; while(k>1){ quick=quick.next; k--; } while(quick.next!=null){ quick=quick.next; slow=slow.next; } return slow.val; } }