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

        int count = 0;
        ListNode cur = pHead;
        while(cur != null){
            count++;
            cur = cur.next;
        }

        int times = count - k;

        while(pHead != null && times > 0){
            pHead = pHead.next;
            times--;
        }

        return count - k >= 0 ? pHead : null;
    }
}