Five years ago I re-wrote this solution as a one liner using linq, and in the comment section I explain how it works.
If you are interested, look there. I'm not sure why this answer has more "Clever" votes. It was just an intermediate step!

This is probably still the worst code I've ever written.

this seems to have been fixed by the upgrade to C# 12:

Test Failed
  Assert.That(actual, Is.EqualTo(expected))
  Expected: < < 37, 93 >, < 4, 12 > >
  But was:  null

Wow! Brilliant.

wtf indeed

C# translation is a mess and needs to be cleaned up:

• unused functions,
• HTML markup leaking from messages,
• Solution funciton is an instance method without a good reason,
• Assertion messages are missing,
• No tests (and no spec) on mutation of inputs

I'm looking at this, and honestly... I have no clue what's being done on the second line before the :

For l > 9, you code returns some value. It should always return 0.

i removed this test case from C# as it went against the specifications.

"and your partner" is a really easy change.

It's easy to be inclusive. If the kata is written using "You" then don't bring gender/race/religion into it.

Coders can figure out how to use variables, they can figure out how to make problem descriptions more inclusive.

The original text is virtue signaling. I'm asking for equality.

If your culture or values are intolerant, that's your problem.
Asking for equality for literally half the people in the world shouldn't be offensive anyones values. I don't think we should welcome a culture of misogyny here.

d is the poorly named static string array.

I'm not sure how this became a solution given it has a syntax error in d.Contains... and changing the d to s the solution doesn't pass the tests.

The description now does. The title can only be changed in the kata editor, and most people are allergic to that.