Level

Find the error

def length_of_longest_substring(s):

    char_index = {}

    max_length = start = 0

    for i, char in enumerate(s):

        if char in char_index:

            start = char_index[char] + 1

        char_index[char] = i

        max_length = max(max_length, i - start + 1)

    return max_length

print(length_of_longest_substring('abcabcbb'))

LeetCode 3: Longest Substring Without Repeating Characters

In this LeetCode-style problem, you need to find the length of the longest substring without repeating characters. Identify the line with a logical error and select the correct implementation to fix it. Pay attention to how the 'start' variable is updated and how it affects the calculation of substring length.