【LeetCode】206.反转链表

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# @Time: 2019/3/19
# @Author: xfLi
# The file...

# 链表头插法

class ListNode:
     def __init__(self, x):
         self.val = x
         self.next = None

def reverseList(head):
    if not head: return head
    cur = head
    pre = None
    while cur is not None:
        temp = cur.next
        cur.next = pre
        pre = cur
        cur = temp
    return pre