Well, it’s been awhile. I’m hoping to start posting here again.
This is an interesting logic puzzle that was naturally generated by a job the Innovation Lab I used to work for requested of me. I decided to turn it into its own thing. It’s heavy on deductive reasoning, moderately light on programming/data science knowledge. Enjoy!
Okay, so put yourself in my shoes: Tim, the guy who runs the Innovation Lab, contacts you and says that the VR station they added this year isn’t working quite right with the sign-in system you designed for them. It looks like it isn’t removing sign-ins from previous days, so the display just constantly shows “0” until Tim goes and signs out enough to bring it back to a positive number of seats. The VR station only has one seat, anyway, and most people sign in to 3D printing. Today, the system shows over 20 sign-ins, which is ludicrous. Tim lets you know that he signs out on the system’s iPad using the same type of ID every time – a bunch of fours in a row – and asks you to go in and fix it. You’re away at college now, but can still access it. You accept it, since you have the free time.
So, you open up the system, and look around, and everything seems… fine. The event display is messed up again, but Tim has done this before, so you fix it for him. The sign-ins and events are two different things, so that definitely wasn’t the problem. There was one weak link you thought Google might’ve broken somehow by removing/changing a feature, but it hasn’t – it looks absolutely fine, along with everything else in the process. You trace the line from the data to the display, and there’s no error – there really were over 20 sign-ins today. There’s no hint of a technical problem.
So, you go over to the raw sign-in data, and see if there’s an answer there. You scroll up to the top, before Tim had to do most of his sign-outs, which are cut off by the bottom of the screen. After looking at it for awhile, you know exactly what went wrong, can guess why, and know it’s up to Tim to fix it. Here’s the screen you were looking at. What’s the problem, the likely cause, and the reason you need Tim to fix it?
Enjoy! Shoutout to this site, for staying up despite the fact I abandoned it for several months, and to college, for sucking up my time. Solution available on request.