题目来源：
https://leetcode.com/problems/reverse-linked-list-ii/
题意分析：
跟定一个链表，和位置m，n。将m到n的节点翻转。
题目思路：
和前面全部翻转的类似。
代码（Python）：
# Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def reverseBetween(self, head, m, n): """ :type head: ListNode :type m: int :type n: int :rtype: ListNode """ if head == None or head.next == None: return head ans = ListNode(-1) t,ans.next = ans,head for i in range(m - 1): t = t.next tmp = t.next for i in range(n- m): tmp1 = t.next t.next = tmp.next tmp.next = tmp.next.next t.next.next = tmp1 return ans.next