What a ride. This took me far, FAR longer than the 3kyu "Tap Into Mr. Mxyzinjin's Matrix". Totally worth it though. Thanks!

And I think it's the same in all math graphs I can remember?

Thirded. In my math courses (e.g. geometry) the x-axis always represented the horizontal axis, but (as @B4B mentioned) the reverse is common given the indexing of 2D arrays, so I went with that instead.

And I think it's the same in all math graphs I can remember?

yep ;)

@docgunthrop:
Your kata description and layout is really good! I just wish the data coming in would already be sanitized so I can concentrate on the meat of the kata (the blob simulation). The input checking felt like busywork, which is a shame because the core of the kata was really fun. Thanks for making it!

@Blind4Basics:
Ah. Different domain then, I guess. Over a decade of game development has really engrained "x is horizontal and y is vertical" into me. And I think it's the same in all math graphs I can remember?

And maybe I'm just operating in a different domain than the other, but x = vertical and y = horizontal really tripped me up.

it's quite usual, actually (matching the way 2D arrays are indexed)

Voile, you're fantastic. This was probably the most fun I've had on Codewars so far!

Admittedly, this kata does have a bit going on. It's not a simple problem in a neat little package, but I did put in effort to keep the Description succinct and make the layout easy on the eyes while keeping ambiguity as minimal as possible.

In any case, congratulations on completing this 3 kyu kata; it's certainly not an easy task.

Well, that was fun. Thanks!

I admit that it is slightly ambiguous, but to me "the test cases ensure" reads like you as the developer can assume that the test case input will always already be sanitized and you don't have to worry about data anomalies.