Longest Substring Without Repeating Characters

Given a string s, your task is to compute the length of the longest substring that contains no repeated characters. A substring is a contiguous sequence of characters from s.

For example, if s = "abcabcbb", the answer is 3, because the longest substring without repeating characters is "abc".

You may use a sliding window approach or any other optimal method. The problem can be formalized as follows:

$$ L = \max_{0 \leq i < n} \{ \text{length of the substring starting at index } i \text{ with all distinct characters} \}.$$

Your solution must read input from standard input (stdin) and output the result to standard output (stdout).

inputFormat

The input consists of a single line containing the string s. The string might be empty or contain any characters including letters, digits, and special symbols.

outputFormat

Output a single integer representing the length of the longest substring of s that contains no repeating characters.

abcabcbb

3