05_从头到尾打印链表

题目：输入一个链表的头结点，从尾到头打印链表每个结点的值。

思路：从头到尾遍历链表，并用一个栈存储每个结点的值，之后出栈输出值即可。

Java版本：

import java.util.Stack;public class Test {    public static class ListNode{        int value;//结点的值        ListNode nxt;//下一个节点    }    //采用栈的方式    public static void printListInverselyUsingIteration(ListNode root){        //创建一个栈        Stack<ListNode> stack = new Stack<>();        if(root == null){            System.out.println("链表为空");        }        while(root != null){            stack.push(root);            root = root.nxt;        }        ListNode tmp;        while(!stack.isEmpty()){            tmp = stack.pop();            System.out.print(tmp.value+" ");        }    }    public static void creatListNode(ListNode root1,int value,ListNode root2){        if(root1 == null){            System.out.println("链表为空");        }        root1.value = value;        root1.nxt = root2;        System.out.print(value + " ");    }    public static void main(String[] args) {        ListNode root1 = new ListNode();        ListNode root2 = new ListNode();        ListNode root3 = new ListNode();        ListNode root4 = new ListNode();        ListNode root5 = new ListNode();        ListNode root6 = new ListNode();        System.out.print("链表反转前：");        creatListNode(root1,12,root2);        creatListNode(root2, 4,root3);        creatListNode(root3,14,root4);        creatListNode(root4, 8,root5);        creatListNode(root5, 2,root6);        creatListNode(root6,30, null);        System.out.println();        System.out.print("链表反转后：");        printListInverselyUsingIteration(root1);        System.out.println();        printListInverselyUsingIteration(null);    }}

Python版本：

# -*- coding: utf-8 -*-class ListNode:    def __init__(self,x=None,next1=None):        self.value = x        self.next = next1def creatListNode(node1,value,node2):    if node1 == None:        print('')    node1 = ListNode(value)    node1.next = node2def printListFromTailToHead(ListNode):    if ListNode.value == None:        return    List=[]    head = ListNode    while head:        # 在第0个位置处插入结点，即最前面        List.insert(0,head.value)        head = head.next    print(List)    return 1List=[15,11,7,18,2,4,11,6]length = len(List)Node =[]for i in range(length):    Node.append(ListNode(List[i]))for j in range(length):    if (j==length-1):        Node[j].next=None    else:        Node[j].next = Node[j+1]print('链表反转前：')print(List)print('链表反转后：')printListFromTailToHead(Node[0])