Actually, not a clever solution, but perky. As I'm learning the language, some techniques are used for practice.

In the description it is said that:

percent of loss increases of 0.5 percent at the end of every two months

Good!

You were right, I've found some issues on my side and managed to solve this kata. That was hell of a ride with compound percents. :)

Thanks for your edits, now it's more comfy to track the solution process.

I've written a fully passing solution (zero failed tests)

Unfortunately your solution is wrong (hence the "Error: execution of an external program failed" ie your program) but the testing function was misplaced so it didn't count the failed tests. Sorry for the inconvenience. I re-edited the Nim translation. Don't forget to reset the page.

Please update Nim version of this kata. I've written a fully passing solution (zero failed tests), but it's being rejected with Error: execution of an external program failed: '/workspace/tests '.

But, as always, good idea is ruined by its 'fans'.

However, I won't say anymore. This is programming site, not a Reddit or /pol/.

Translation added

Find all duplicates from our message! [...] The words in the secret message should be ordered in the order in which they are found as a duplicate.

That's all fine and nice, but

the casing of words should not matter for the purpose of this kata

The current test cases indicate that lowercase words should be returned, whereas your current description can be understood that "This This" results in "This". Either use toLowerCase() on the user's solution (after all, the casing of words should not matter), or add that the result should be in lower case.

Sure, I haven't done much coding in the language so I can't verify the translation.

Do want this for Python as well.