题解 | #最长无重复子串#

Python
遍历列表，采用字典存放正在查找的子串。无重复添加到字典；有重复，获取重复值的前一个下标，其后位置到当前下标更新至字典。

class Solution:
    def maxLength(self , arr ):
        # write code here
        dic = {arr[0]: 0}
        len_max = 1
        for i in range(1, len(arr)):
            if arr[i] not in dic:
                dic[arr[i]] = i
            else:
                len_max = max(len_max, len(dic))
                j = dic[arr[i]]
                dic = {arr[a]: a for a in range(j+1, i+1)}
        len_max = max(len_max, len(dic))       
        return len_max