Find longest substring without repeats: Mixed repeats

What this Python exercise asks you to practise

This scenario tests find longest substring without repeats. It belongs to the Algorithm Foundations: Arrays, Searching, Sorting, and Hashing roadmap and uses the sliding window · hash map pattern.

Complexity, linear and binary search, sorted() trade-offs, prefix ideas, two pointers, sliding windows, and hash-map patterns.

Pattern relevance

This exercise strengthens sliding window · hash map. Be ready to explain the input, the rule, the boundary cases, and why the chosen approach is appropriate.