leetcode 【 Insertion Sort List 】 python 实现

 1 # Definition for singly-linked list.
 2 # class ListNode:
 3 #     def __init__(self, x):
 4 #         self.val = x
 5 #         self.next = None
 6 
 7 class Solution:
 8     # @param head, a ListNode
 9     # @return a ListNode
10     def insertionSortList(self, head):
11         
12         
13         if head is None or head.next is None:
14             return head
15         
16         dummyhead = ListNode(0)
17         dummyhead.next = head
18         
19         curr = dummyhead.next
20         while curr.next is not None:
21             if curr.next.val < curr.val:
22                 pre = dummyhead
23                 while pre.next.val < curr.next.val:
24                     pre = pre.next
25                 tmp = curr.next
26                 curr.next = tmp.next
27                 tmp.next = pre.next
28                 pre.next = tmp
29             else:
30                 curr = curr.next
31         
32         return dummyhead.next