链表中倒数第k个节点

题目：

输入一个链表，输出该链表倒数第k个节点。

解答：

 1 public class Solution {
 2 
 3     public static ListNode findKthToTail(ListNode pHead, int k) {
 4         if(pHead == null || k == 0) {
 5             return null;
 6         }
 7 
 8         ListNode pAhead = pHead;
 9         ListNode pBehind = null;
10         for(int i = 0; i < k; i++) {
11             if(pAhead.next != null) {
12                 pAhead = pAhead.next;
13             } else {
14                 return null;
15             }
16         }
17 
18         pBehind = pHead;
19         while(pAhead.next != null) {
20             pAhead = pAhead.next;
21             pBehind = pHead.next;
22         }
23 
24         return pBehind;
25     }
26 }