Performance tag added. Thanks for the feedback!

Description edited.

Thanks! I will add that line to the description.

Thanks a lot! I will clarify that point.

Seriously I think this kata deserves a level beyond 5kyu at least in rust.

In the worst situation creating four iterators but using only the first & last yields

Kinda an abuse of iterators

Approved! Thanks.

Only translations need approval.
You need to submit your solution once it's passed all test cases.
I cannot find your solution in the Solutions so I guess you haven't submitted it yet.

Thank you!
Yes, your approach will do the right job.
However my implementation of the "inside-out" algorithm is correct.
The line I made wrong is inside the 2nd loop:

var n = seq[i] + 1; // No cheating!