题解 | 链表内指定区间反转

class Solution:
    def reverseBetween(self , head: ListNode, m: int, n: int) -> ListNode:
        #加个表头
        res = ListNode(-1)
        res.next = head
        #前序节点
        pre = res 
        #当前节点
        cur = head 
        #找到m
        for i in range(1,m): 
            pre = cur
            cur = cur.next
        #从m反转到n
        for i in range(m, n): 
            temp = cur.next
            cur.next = temp.next
            temp.next = pre.next
            pre.next = temp
        #返回去掉表头
        return res.next 

Python代码