Could be a sneaky recruiting trick. Stuff like this has happened before:
https://www.vox.com/2015/8/26/11618060/puzzles-are-fun-searc...
https://www.vox.com/2015/8/26/11618060/puzzles-are-fun-searc...
The last problem on mine was really interesting, took me days. I wonder if there's a list of the problems somewhere, I thought I remember hearing that they weren't all the same.
I never did continue with the recruiting part of it, just had some fun.
The last level for me was to write a function that evaluated
sum([floor(i*sqrt(2)) for i in range(1,n+1)])
for 0 < n < 10**100. It was the first time I ever had use for my Knuth books.It was quite detrimental to work performance though. Never heard from a recruiter, but I guess they don't employ developers in Norway.