题解 | 链表内指定区间反转

# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param head ListNode类 
# @param m int整型 
# @param n int整型 
# @return ListNode类
#
class Solution:
    def reverseBetween(self , head: ListNode, m: int, n: int) -> ListNode:
        lm = head
        ln = head
        H = 1
        a = m
        b = n
        m = 1
        n = 1
        while a < b:
            while m < a:
                lm = lm.next
                m += 1
            while n < b:
                ln = ln.next
                n += 1
            
            k = ln.val
            ln.val = lm.val
            lm.val = k
            a += 1
            b -= 1
            n = m
            ln = lm

        return head