92. 反转链表 II(Python)

Definition for singly-linked list.

class ListNode(object):

def init(self, val=0, next=None):

self.val = val

self.next = next

class Solution(object):
def reverseBetween(self, head, left, right):
"""
:type head: ListNode
:type left: int
:type right: int
:rtype: ListNode
"""
right = right -1
left = left -1

while( right-left>=0 ):
print(right-left)
# 左侧节点
l = head
for i in range(left):
l = l.next
# 右侧节点
r = head
for i in range(right):
r = r.next
# print(l.val, r.val)
l.val, r.val = r.val, l.val
right = right-1
left = left+1
print(head)
return head