Block: 
[[0, 0, 0], [0, 3, 0], [0, 0, 0]],

Observations: 
[['1A', 1], ['1A', 0], ['1A', 1], ['1A', 0], ['1B', 3], ['2B', 0], ['2B', 1], ['2B', 0], ['2B', 1]]

Switches 1A and 2B 4 times. And the answer should be: [ '1B', '2A' ] BUT in "observations" there is ['1B', 3]. That is, a person appeared in the window(with a light). He shouldn't be in the answer. The answer should be:[ '2A' ].

Did I misunderstand something? Or is there a problem with my solution?

he probably copy pasted the content of this fork and did an edit himself xD

\o/

Rejected, merge conflict & author changed the description without approving this fork.

_{Have 2 consolation upvotes for the effort instead. 🙂}

The issue has been resolved. I enjoyed your Kata.

how about now?

For the Coffeescript version of this Kata, I am receiving a "ReferenceError: flattenArray is not defined" error for approximately 10% of the Random Tests.

Thanks :D

First solver, well done!

I wrote the code for large integers, but when creating this kata, I realized that it had execution time limit, and it can't handle larger test cases like "71717", which returns "1038660". That's why the return type is string instead of interger.

Why such a complex solution if the sample space are just 32 bit integers?

This is an old kata, the reference scale for difficulty levels was a bit different back then. Enjoy the cheap ranking points!

O(n) variation aimed at 6 kyu, perhaps 5. Or do you have any other suggestions for interesting variations?