# -*- coding:utf-8 -*-

class ListNode:

    def __init__(self, x):

        self.val = x

        self.next = None

# 单向链表链表 node1: 1->2->3

node1 = ListNode(1)

node2 = ListNode(2)

node3 = ListNode(3)

node4 = ListNode(4)

node5 = ListNode(5)

node1.next = node2

node2.next = node3

node3.next = node4

node4.next = node5

class Solution:

    # 返回ListNode

    def ReverseList(self, pHead):

        # write code here

        if not pHead or not pHead.next:

            return pHead

        last = None

        while pHead:

            temp = pHead.next

            pHead.next = last

            last = pHead

            pHead = temp

        return last

if __name__ == '__main__':

    origin = node1

    print('反转前：', end = ' ')

    while origin:

        print(origin.val, end = ' ')

        origin = origin.next

    result = Solution().ReverseList(node1)

    print('\n反转后：', end = ' ')

    while result:

        print(result.val, end = ' ')

        result = result.next