3、从尾到头打印链表

输入一个链表，按链表从尾到头的顺序返回一个ArrayList。

===============Python=============

# -*- coding:utf-8 -*-
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    # 返回从尾部到头部的列表值序列，例如[1,2,3]
    def printListFromTailToHead(self, listNode):
        # write code here
        if not listNode:
            return []
        res = []
        while listNode:
            res.append(listNode.val)
            listNode = listNode.next
        return res[::-1]

==============Java============

/**
*    public class ListNode {
*        int val;
*        ListNode next = null;
*
*        ListNode(int val) {
*            this.val = val;
*        }
*    }
*
*/
import java.util.ArrayList;
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> res = new ArrayList<>();
        if (listNode == null) {
            return res;
        }
        addList(res, listNode);
        return res;
    }
    public void addList(ArrayList<Integer> res, ListNode listNode) {
        if (listNode != null){
            addList(res, listNode.next);
            res.add(listNode.val);
        }
    }
}