# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
#
# @param head ListNode类
# @return ListNode类
#
class Solution:
def oddEvenList(self , head ):
# write code here
if not head or not head.next or not head.next.next:
return head
left_head = ListNode(-1)
left_tail = left_head
right_head = ListNode(-1)
right_tail = right_head
temp = head
while temp:
new_temp = temp.next
left_tail.next = temp
left_tail = left_tail.next
temp = new_temp
if not temp :
break
new_temp = temp.next
right_tail.next = temp
right_tail = right_tail.next
temp = new_temp
left_tail.next = right_head.next
right_tail.next = None
return left_head.next