算法题: 无重复字符串的最长子串

📌 给定一个字符串 s ，请你找出其中不含有重复字符的 最长子串的长度。

def lengthOfLongestSubstring(s: str) -> int:
    seen = {}
    l = 0
    output = 0
    for r in range(len(s)):
        """
        If s[r] not in seen, we can keep increasing the window size by moving right pointer
        """
        if s[r] not in seen:
            output = max(output, r-l+1)
        else:
        # There are two cases if s[r] in seen:
        # case1: s[r] is inside the current window, we need to change the window by moving left pointer to seen[s[r]] + 1.
        # case2: s[r] is not inside the current window, we can keep increase the window
            if seen[s[r]] < l:
                output = max(output,r-l+1)
            else:
                l = seen[s[r]] + 1
        seen[s[r]] = r

    return output


lengthOfLongestSubstring("pwwkew")