Longest Substring Without Repeating Characters Problem Statement

Given a string S of length L, determine the length of the longest substring that contains no repeating characters.

Example:

Input:

"abacb"

Output:

3

Explanation:

The longest substring without repeating characters is "acb" with a length of 3.

Constraints:

• 0 <= L <= 105
• Time limit: 1 sec

Note:

You do not need to print anything. The function should be implemented to return the answer.