题解 | #链表中倒数最后k个结点#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param pHead ListNode类 
     * @param k int整型 
     * @return ListNode类
     */
    public ListNode FindKthToTail (ListNode pHead, int k) {
        // write code here
        ListNode nextNode = pHead;
        while (k != 0 && nextNode != null) {
            nextNode = nextNode.next;
            k--;
        } 
        if (k == 0 && nextNode == null) {
            return pHead;
        } else if (nextNode == null) {
            return null;
        } else {
            while (nextNode != null) {
                pHead = pHead.next;
                nextNode = nextNode.next;
            }
            return pHead;
        }
    }
}