用python语言解答LeetCode的86题
方法一：
方法一的代码：
#coding:utf-8
class ListNode:
def __init__(self, x):
self.val = x
self.next = None
class Solution:
def partition(self, head, x):
"""
:param head: ListNode
:param x: int
:return: ListNode
"""
before = before_head = ListNode(0)
after = after_head = ListNode(0)
while head:
if head.val < x:
before.next = head
before = before.next
else:
after.next = head
after = after.next
head = head.next
after.next = None
before.next = after_head.next
return before_head.next
