Ask HN: What are the most interesting take home coding challenges you have seen?

[fjahr]

We want to improve the coding challenge we give candidates as part of our interview process. The challenge is usually a take-home exercise in our process.

We are looking for inspiration on interesting problems that not everyone has solved already, where you can easily copy+paste the solution online and that can be solved in less than a days work.

Thanks!

[whatnotests]

My favorite was the Mars Rover challenge.