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 dummy = new ListNode(-1);
        dummy.next = pHead;
        Integer l = -1;
        while (dummy!=null){
            dummy = dummy.next;
            l+=1;
        }
        if (l<k){
            return null;
        }
        dummy = new ListNode(-1);
        dummy.next = pHead;

        Integer i = -1;
        while (dummy!=null){
            if (i ==l-k){
                return dummy;
            }
            dummy = dummy.next;
            i+=1;
        }
        return dummy;
    }
}

模拟法