题解 | #牛牛的冒险旅程#

# 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 
# @return int整型
#
class Solution:
    def gcdInCycle(self , head: ListNode) -> int:
        # write code here
        cur=head
        n=0
        list1,list2=[],[]
        while cur:
            cur=cur.next
            n=n+1
        cur=head
        for i in range(n):
            list1.append(cur.val)
            if cur.val not in list2:
                list2.append(cur.val)
                cur=cur.next
        if len(list2)==n:
            return -1

        a=min(list2)
        for i in range(a,0,-1):
            flag=1
            for j in range (len(list2)):
                if list2[j]%i!=0:
                    flag=0
            if flag==1:
                return i