It is unclear
I wasn't one of the voters, but given the current question state I would also vote to close as unclear.
I've read the challenge description several times and I still don't know what it's asking for. Part of that is the challenge description, which consists only of the first paragraph, is all one run-on sentence. Breaking that out into bullet points could help, or restructuring it to be more than one sentence.
Secondly, I don't think that "Do not use standard library functions for permutations or combinatorics." is a good fit for the challenge. Depending upon the language, there is a lot of grey area where arguing semantics can come into play. This is a non-observable requirement, and is one of the things to avoid when writing good challenges.
Finally, I'm not convinced that the boundaries of the challenge (up to 123456789
, if I'm understanding correctly) will provide a challenging enough scenario to allow for fastest-code. I believe that submissions will likely run into ceilings surrounding startup/shutdown code variations rather than providing enough variations in timing of the actual algorithm. This will either make the challenge less language-agnostic, or will cause submissions to be all within margin of error.