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
        if(pHead == null || k <= 0) return null;
        ListNode temp = pHead;
        List<ListNode> nodeList = new ArrayList<>();
        nodeList.add(temp);
        while(true){
            ListNode next = temp.next;
            if(next == null) break;
            nodeList.add(next);
            temp = next;
        }

        ListNode target = null;
        if(k > nodeList.size()) return null;

        return nodeList.get(nodeList.size()-k);
    }
}