The problem comes from your code. You are casting a negative number to usize, which results in a really big unsigned number. And then you use this number as the bound in a loop in which you allocate memory, hence the allocation failure.

Return null/nil/None/... if the input is an even number or negative, as it is not possible to print a diamond of even or negative size.

My Rust solution should work, but adding the appropriately placed newline characters gives this result. This only pops up when the answer is correct - if I add a newline character at the start of the string, the test fails and no error occurs.

memory allocation of 9223372036854775806 bytes failed

Caused by:
process didn't exit successfully: /workspace/target/debug/deps/challenge-07bd72047d917620 --show-output -Z unstable-options --format json (signal: 6, SIGABRT: process abort signal)

Kata only provides a fixed set of test cases, which is easy to hard-code.

https://github.com/MoonPresident/Latin-Square-Generator

Calling "generate_latin_square" will generate a solution, and calling "cull_latin_square" will generate a problem. Passing the solution into "get_tower_clues" will give you the hints that surround the problem.

Incidentally, I have updated the code to go up to 15x15.

Sorry for the late reply. I currently have no plans to publish a python version, but if you have a python version that works, I'd be happy to work with you on the translation. I can provide you with some test cases if you would like.

I have updated the encoding to reduce the nesting by another layer and included much harder problems. Up to 15 x 15 now!

Count of permutations? How do you mean? This is designed to use skyscaper problems with only one solution.

Hey.
Yes. It is a good improvement. But in current problems count of permutations too low. The most of test cases get solved after excluding wrong combinations.

Hey Crastinus. Thank you for the feedback.

You reminded me I had meant to update this task for a while, so I have rewritten the test cases to extend up to 15x15 and to improve the difficulty. Could you have another go and tell me if its a meaningful improvement?

Too easy task. All test cases fits into 30ms in Release buld.

I tried to reproduce, but of all the clues, none of them equal all zeroes. So I'm not sure what the issue was you encountered.

I can confirm it can be solved.

Hi Mr President:) I think I have a solution in Python (not the one where only the clues are given), but I do not know C++. So, I would like to know whether you plan to publish a Python version some day?

That is good information, I can definitely use that to refine the load time.

As for the difficulty, I know that the previous test cases were comparatively easy, so I tried to turn the difficulty up so that it was closer to the challenge level of the 6 by 6 and 7 by 7 katas. I am still fine tuning the difficulty, and have ideas for how to make the challenges more moderate or more difficult, as well to standardise the average level of challenge. It all depends on the feedback I get.