import java.util.ArrayList;
import java.util.Stack;/*** 输入一个链表，从尾到头打印链表每个节点的值*/
class Test13 {public static void main(String[] args) {//创建单链表ListNode node1 = new ListNode(1);ListNode node2 = new ListNode(2);ListNode node3 = new ListNode(3);node1.next = node2;node2.next = node3;//采用递归的方式实现PrintListTailtoHead p = new PrintListTailtoHead();ArrayList<Integer> list = p.printListFromTailToHead(node1);System.out.println(list.toString());System.out.println("-------------");//借助堆栈的“后进先出”实现（容易理解）PrintListTailtoHead2 p2 = new PrintListTailtoHead2();ArrayList<Integer> list2 = p2.printListFromTailToHead2(node1);System.out.println(list2.toString());}
}//节点
class ListNode {int value;ListNode next = null;ListNode() {}ListNode(int value) {this.value = value;}
}//方法1：采用递归的方式实现
class PrintListTailtoHead {public ArrayList<Integer> printListFromTailToHead(ListNode headNode) {ArrayList<Integer> list = new ArrayList<Integer>();//递归if (headNode != null) {if (headNode.next != null) {list =printListFromTailToHead(headNode.next);}list.add(headNode.value);}return list;}
}//方法2：借助堆栈的“后进先出”实现
class PrintListTailtoHead2{public ArrayList<Integer> printListFromTailToHead2(ListNode headNode) {//存入栈中Stack<Integer> stack=new Stack<Integer>();while (headNode!=null){stack.push(headNode.value);headNode=headNode.next; //重要，不要忘记
        }//从栈中取出存入集合中ArrayList<Integer> arrayList=new ArrayList<Integer>();while (!stack.empty()) {arrayList.add(stack.pop());}//返回结果return arrayList;}
}