alt

#     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 the head
# @return bool布尔型
#
class Solution:
    def isPail(self , head: ListNode) -> bool:
        if head is None: return None
        temp=[]
        while head:
            temp.append(head.val)
            head=head.next
#         if len(temp)%2==0:
        left,right=0,len(temp)-1
        while left<right:
            if temp[left]!=temp[right]:
                return False
            left,right=left+1,right-1
#         if len(temp)%2==1:
        return True