The feeling I had wracking my brain to solve this only to find the top solution was near exactly what I had come up with :')

I like the logic behind your solution. Very similar to mine

oh my good 'o'

wow that's really clever! and so much less code than what I had!

Yes, So I tried a loop within a loop and jumped n windows each run in inside loop, n being the student number. I think i screwed up while doing a close/open of the door.

Try it with a few small numbers on paper, and hopefully, you'll spot the pattern.

How do you optimise it ?

Very interesting Kata for 6 kyu. Also need some optimization for performance purpose.

There is 1000 tests, and n can go up to 100_000. Check how long your solution runs for n=100k.

Your solution being too slow is not a kata issue.

Approved

this is not performant. it goes over list multiple times

Groovy Translation