题解 | 双指针解法

双指针解法 通过所有算例，耗时短，供参考

    def lengthOfLongestSubstring(self , s: str) -> int:
        cnt = 1
        i = 0
        k = 1
        
        while i < len(s)-1 and k < len(s):
            if s[k] not in s[i: k]:
                cnt = max(cnt, len(s[i: k+1]))
                k += 1
            elif s[k] in s[i: k]:
                i += 1
                k = i+1
        
        return cnt