【剑指Offer】13反转链表

题目描述

输入一个链表，反转链表后，输出新链表的表头。

时间限制：1秒；空间限制：32768K；本题知识点：链表

解题思路

# -*- coding:utf-8 -*-
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
    # 返回ListNode
    def ReverseList(self, pHead):
        # write code here
        if pHead==None or pHead.next==None:
            return pHead
        pre = None
        cur = pHead
        while cur:
            tmp = cur.next
            cur.next = pre
            pre = cur
            cur = tmp
        return pre