[Algo] Longest Substring Without Repeating

[Jeanedlune]

Problem: Longest Substring Without Repeating Characters

Find the length of the longest substring without repeating characters.

Given a string, find the length of the longest substring that contains no repeating characters.

Constraints

• 0 <= s.length <= 5 * 10^4
• s consists of English letters, digits, symbols and spaces

Example

Input: s = "abcabcbb"
Output: 3 (substring "abc")

Input: s = "bbbbb"
Output: 1 (substring "b")

Complexity

• Time: O(n)
• Space: O(min(m, n)) where m is charset size

Contribution Guidelines

• Implement in one language (we'll add others later)
• Include README with problem statement and test cases
• Add test harness in your implementation
• Follow code style guide in .gemini/styleguide.md