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.
Short and clear, but pretty bad performance.
This will have to scan all of b for each element in a.
I'm baffled by how often in this site the "top" solution is just the shortest one, as if number of lines is the ultimate measure of good practice.
I'm seeing a lot of people suggesting this kata is too easy to be 6-kyu.
I suggest to those people to solve this with your own algorithm, without using the known 1-line formula.