# 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 arr int整型一维数组 the array
# @return int整型
#
class Solution:
    def maxLength(self , arr: List[int]) -> int:
        # write code here
        pre_dis = 0
        maxl = 0
        dis = {}
        for i in range(len(arr)):
            num = arr[i]
            if num in dis:
                pre_dis = max(pre_dis,dis[num])
            maxl = max(maxl,i+1-pre_dis)
            dis[num]=i+1
        return maxl