题解 | 最长无重复子数组

#
# 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
        if not arr:
            return 0
        left = 0
        maxLen = 0
        hashMap = {}
        for right in range(len(arr)):
            if arr[right] in hashMap:
                left = max(left, hashMap[arr[right]] + 1)
            hashMap[arr[right]] = right
            maxLen = max(maxLen, right - left + 1)
        return maxLen