Longest Substring Without Repeat

Given a string A, find the length of the longest substring without repeating characters.

Note: Users are expected to solve in O(N) time complexity.

1 <= size(A) <= 10⁶

String consists of lowerCase,upperCase characters and digits are also present in the string A.

Single Argument representing string A.

Return an integer denoting the maximum possible length of substring without repeating characters.

Input 1:

 A = "abcabcbb"

Input 2:

 A = "AaaA"

Output 1:

 3

Output 2:

 2

Explanation 1:

 Substring "abc" is the longest substring without repeating characters in string A.

Explanation 2:

 Substring "Aa" or "aA" is the longest substring without repeating characters in string A.