翻转一个链表
样例
给出一个链表1->2->3->null，这个翻转后的链表为3->2->1->null
步骤是这样的：
1. 新建空节点：None
2. 1->None
3. 2->1->None
4. 3->2->1->None
代码就非常简单了：
1 # -*- coding:utf-8 -*- 2 # class ListNode: 3 # def __init__(self, x): 4 # self.val = x 5 # self.next = None 6 class Solution: 7 # 返回ListNode 8 def ReverseList(self, pHead): 9 # write code here 10 temp = None 11 while pHead: 12 cur = pHead.next 13 pHead.next = temp 14 temp = pHead 15 head = cur 16 return temp
