0003_longest_substring_without_repeating_characters.py

class Solution:
    def lengthOfLongestSubstring(self, str1: str) -> int:
        start_ind = 0
        counter = 0
        max_counter = 0
        str1_dict = {}
        for ch in str1:
            counter += 1
            if str1_dict.get(ch):
                str1_dict[ch] += 1
                while str1_dict[ch] > 1:
                    str1_dict[str1[start_ind]] -= 1
                    if not str1_dict[str1[start_ind]]:
                        str1_dict.pop(str1[start_ind])
                    counter -= 1
                    start_ind += 1
            else:
                str1_dict[ch] = 1

            max_counter = max(counter, max_counter)
        return max_counter


if __name__ == '__main__':
    solution = Solution()
    my_nums = "abcabcbb"
    res = solution.lengthOfLongestSubstring(my_nums)
    print(res)