Wow, really clean! Awesome!!

Nice suggestion!

Wow, I just learned from your code. Good stuff.

Clever, way better than my solution

You're telling me.

(Coming from somebody who is currently stuck only on improving performance and is getting increasingly closer to smashing my head through the wall)

Honestly, i am totally lost.Could anyone explain the purpose of that for loop for me please.

Thanks for your feedback!

The performance aspect of this problem makes it an especially enjoyable and useful Kata.

I can see where you're coming from. I feel like the definition of a Kata is hardly clear, and is still evolving. When creating a Kata, one of the "Disciplines" is Puzzles: "Code that is fun to play and involves solving puzzles that may not be strictly programming challenges." There are several Kata already on here that are not really difficult to program, it's just finding the "secret" that's a challenge. This is very similar in that respect, but in a way, each of the rules could be a Kata on their own. (And some of them are. hint hint) If there were just a single one for each test, this wouldn't be much of a puzzle at all; it is the particular combination that makes it interesting to try and figure out what rule does what.

But you are right that implementing a decoder for each one is much easier than figuring out what you need to do. That's kind of the point, though. I think this is the perfect example of a puzzle for people who like mental challenges, but aren't necessarily experts at math or programming. (Like many of the 4 kyu and up Kata demand.)

Furthermore, programming skills are not limited to knowledge of a particular language. Logical reasoning skills play a huuuuge role when programming in any language, particular when you're trying to troubleshoot a bug. I get that it's a little outside of the box, but I think there is value in training logic skills even without challenging programming, and that it will improve your programming in a subtle way. On a side note, I don't think there is anywhere more suitable for this kind of puzzle. (I mean really, what are you going to do, give someone ten choices and then have them guess which one of those was used to encode the text? That would be boring and easy. It's much more interesting and rewarding to solve off of a blank slate!)

I've started working on this problem and my initial impression is that the balance is off in terms of difficulty in code-breaking vs. software difficulty. I would think the balance would be closer to right if there were just a single ID to decipher, or if the tests incrementally added one ID at a time. As it is, I would rank this problem as very hard for all but avid cypher breakers. For the one or two IDs that I believe I have a handle on (i.e., that I suspect I've deciphered), I envision small difficulty implementing decoders. This imbalance doesn't meant the problem is a bad problem, but, in my opinion at least, it does mean this isn't the right forum for it. It's certainly a stretch to call this problem a "Kata".

Problem wording remains hard to understand and would benefit from editing.

Yeah, you are not the first person who mentions this ))

I clarified indexes / positions problem in the description of the Kata. In addition I added 'Logic' task:)

Thank you for the feedback!:)

The instructions ask for 'an index' of the correct number, which would normally be interpreted as meaning that if the correct answer is the first on the list, the index would be 0, as opposed to 1. You could call it the 'position' or 'location' of the number on the list (or some word other than index), or change the solution so that the first item corresponds to 0.

Also, this might benefit from a 'Logic' tag.