从尾到头打印链表.py

'''
输入一个链表，按链表值从尾到头的顺序返回一个ArrayList。
'''

# -*- 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 []
        
        result =[]
        
        while listNode:
            result.insert(0, listNode.val)
            listNode = listNode.next
        return result  

# -*- 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 []
        arraylist = []
        while listNode:
            arraylist.append(listNode.val)
            listNode = listNode.next
        arraylist.reverse()
        return arraylist      
#用栈  
 # -*- 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 []
        arraylist = []
        newlist = []
        while listNode:
            arraylist.append(listNode.val)
            listNode = listNode.next
        while arraylist:
            newlist.append(arraylist.pop())
        return newlist