Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
I think it would be easier with PostgreSQL allowing the use of window functions. The description should be a little more clear or, at least in the test cases, show the expected output.
Anyways, great kata! :)