題目：

題解：

class Solution:def reverseBetween(self, head: ListNode, left: int, right: int) -> ListNode:# 設置 dummyNode 是這一類問題的一般做法dummy_node = ListNode(-1)dummy_node.next = headpre = dummy_nodefor _ in range(left - 1):pre = pre.nextcur = pre.nextfor _ in range(right - left):next = cur.nextcur.next = next.nextnext.next = pre.nextpre.next = nextreturn dummy_node.next