leetcode刷题，没想到这么难搞！

【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>>

leetcode之前提交的代码不见了，所以在这里记一下
https://leetcode.com/problems/longest-substring-without-repeating-characters/

class Solution(object):
    def lengthOfLongestSubstring(self, s):
        """
        :type s: str
        :rtype: int
        """
        rtv = start = current = 0

        last_seen = {}
        while current < len(s):
            char = s[current]
            if char in last_seen:
                start = max(start, last_seen[char] + 1)
            if current - start + 1 > rtv:
                rtv = current - start + 1
            last_seen[char] = current
            current += 1
        return rtv

来源：oschina

链接：https://my.oschina.net/u/273719/blog/758263