【LEETCODE】147- Insertion Sort List [Python]

Sort a linked list using insertion sort.

题意：

用插入排序

参考：

http://bookshadow.com/weblog/2015/01/06/leetcode-insertion-sort-list/

Python：

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def insertionSortList(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        
        if head is None or head.next is None:
            return head
        
        dummy=ListNode(0)
        dummy.next=head
        cur=head
        
        while cur.next:
            
            if cur.val>cur.next.val:
            
                pre=dummy
                while pre.next.val<cur.next.val:
                    pre=pre.next
                m=cur.next
                cur.next=m.next
                m.next=pre.next
                pre.next=m
            else:
                cur=cur.next
        
        return dummy.next