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) {
        ListNode cur = pHead;
        int size = 0;
        while(cur!=null){
            cur = cur.next;
            size += 1;
        }
        int index = size -k + 1;
        size =  0;
        cur = pHead;
        while(cur!=null){                     
            size += 1;
            if(size == index)
                return cur;  
            cur = cur.next;                 
        }
        return null;
    }
}