codewars

Kata solutions organized by kyu (difficulty), then by slug.

Structure

8kyu/       easiest — fundamentals
7kyu/
6kyu/
5kyu/
4kyu/
3kyu/
2kyu/
1kyu/       hardest
  └── <slug>/
        solution.<ext>       one file per language

Indexed in code.db at krisyotam.com/code.