Great! Valid for both lower and uppercase!

The "drink beer" is repeated, isn't it? And shouldn't be a big number (e.g. 1000) instead of 30 for whisky?

Thanks for your reply!

when working with a fork, you can also create your own tests, just as you can in the sample tests of a regular kata trainer. so, just create this test (or any other) and find out for yourself

Thanks for the note, this will be my first fork here!
I think this code would return true for string parameters ("aaab", "bbba"), and I think it should return false, shouldn't it?

yes. if you want to study the code in more detail, fork the solution and play around with the code, use cout, see how it works... (there's no need to publish your fork unless you have created an interesting variant)

Does this really work?

Interesting way to express a range