[goodwink]

The original code is like this because it's an exercise. Of course ruby has hashes.

[dclara]

The CTF does not give a description of the problem, but the code instead. And it persuades the new users not to change algorithm too much, just save a few steps, which implies to have minor changes of the code only.

Look at my another comment, hash may not be always better than list.

[zwily]

Sure a hash isn't always better than a list. In this case, it most definitely is. :)