Find first and last occurrence: Single occurrence

What this Python exercise asks you to practise

This scenario tests find first and last occurrence. It belongs to the Algorithm Foundations: Arrays, Searching, Sorting, and Hashing roadmap and uses the binary search · boundary pattern.

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

Pattern relevance

This exercise strengthens binary search · boundary. Be ready to explain the input, the rule, the boundary cases, and why the chosen approach is appropriate.