I wasn't really expecting that one to be added, but maybe a somewhat more strenuous test is needed to weed out attempts (like my first) that are actually plain wrong.

EDIT: Also, I just looked, the 2kyu version doesn't include Javascript, which is a shame. Not there yet with Python.

I re-submitted a solution, since although my original passed the tests, it would have definitely failed on some puzzles. E.g. the (supposed) hardest ever puzzle (below).

var puzzle = [
    [8,0,0,0,0,0,0,0,0],
    [0,0,3,6,0,0,0,0,0],
    [0,7,0,0,9,0,2,0,0],
    [0,5,0,0,0,7,0,0,0],
    [0,0,0,0,4,5,7,0,0],
    [0,0,0,1,0,0,0,3,0],
    [0,0,1,0,0,0,0,6,8],
    [0,0,8,5,0,0,0,1,0],
    [0,9,0,0,0,0,4,0,0],
];
var solution = [
    [8,1,2,7,5,3,6,4,9],
    [9,4,3,6,8,2,1,7,5],
    [6,7,5,4,9,1,2,8,3],
    [1,5,4,2,3,7,8,9,6],
    [3,6,9,8,4,5,7,2,1],
    [2,8,7,1,6,9,5,3,4],
    [5,2,1,9,7,4,3,6,8],
    [4,3,8,5,2,6,9,1,7],
    [7,9,6,3,1,8,4,5,2],
];

It's probably too late but maybe harder tests might filter out false solutions like my original submission.

And ... it works.

Not sure what to take from this, except 'turn it off and on again' :)

Thanks a lot for sticking with this.

Ps. I will look at some of the amazingly concise solutions for some of the tools you mentioned.

I updated it with a much smaller example (and put the back-ticks in).

I was trying to fulfill the bonus bits ...

-Avoid creating an array whose memory footprint is roughly as big as the input text.
-Avoid sorting the entire array of unique words.

Hers's an example of input that fails:

'BxhhnNv':,?'BxhhnNv'._.?.'BxhhnNv'.'BxhhnNv'??'BxhhnNv',,,!;'BxhhnNv'-'BxhhnNv'-;'BxhhnNv'_-'BxhhnNv'..!,!'BxhhnNv'._: -'BxhhnNv'-;'BxhhnNv';'BxhhnNv'_'BxhhnNv':..,.'BxhhnNv'_,??

The fail message is:

Incorrect match: words not present in the string. Your output: ['bxhhnnv']. One possible valid answer: ["'bxhhnnv'"]

As I say though, locally I get the valid answer.

Thanks for that, I ended up using a html pre tag - it's readable now.

Is there a help section for formatting these text boxes?

I didn't know about the spoiler tag -> no notification. I'll post my code in a seperate reply and spoiler tag that.

Anyway, I'm not using global variables and I'm not sure what you mean by hidden variables. Also, I did try to look through the changelog - there was nothing that stood out to me.

I'm getting some fails that only occur on the server when one or more of the returned words contain an apostrophe.

For example, Incorrect match: words not present in the string. Your output: ['xlo', "u'y", 'wfwzsg']. One possible valid answer: ['xlo', "u'ywfwzsg", 'ndqih']

But, when I run this example locally (PyCharm, Windows), I get output ['xlo', "u'ywfwzsg", 'ndqih'].

Can anyone help me understand why this is happening?

Got it. Thanks.

Example test case: no_musical(2040, 2174, 3, 17) which is supposed to result in 0 classes missing musicals.

But, seeing that the last musical occurs in year 2172, surely the classes of 2173, 2174 both miss out, hence the result should be - at least - 2.

Btw, I've labelled this as a question as I may have misunderstood something.

Thanks for this. Forced me to learn about a new toy.