import java.util.ArrayList;

import java.util.Stack;

class ListNode {

    int val;

    ListNode next;

    ListNode(int val) {

        this.val = val;

      }

}

public class FromTailToHead {

    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {

        ArrayList<Integer> list = new ArrayList<Integer>();

        if(null==listNode ){

            return list;

        }

        Stack<Integer> stack = new Stack<Integer>();

        ListNode nextNode = listNode;

        while(null!=nextNode){

            stack.push(nextNode.val);

            nextNode = nextNode.next;

        }

        while(!stack.isEmpty()){

            list.add(stack.pop());

        }

        return list;

    }

}

/*

 * 递归实现

 */

public class FromTailToHead2 {

    public static void printListFromTailToHead(ListNode Head) {

        if(null!=Head){

            if(null!=Head.next){

                printListFromTailToHead(Head.next);

            }

            System.out.print(Head.val+"\t");

        }

    }

    public static void main(String[] args) {

        ListNode n1 = new ListNode(1);

        ListNode n2 = new ListNode(2);

        ListNode n3 = new ListNode(3);

        n1.next=n2;

        n2.next=n3;

        n3.next=null;

        ListNode Head =n1;

        while(Head!=null){

            System.out.print(Head.val+"\t");

            Head=Head.next;

        }

        System.out.println();

        printListFromTailToHead(n1);

    }

}