Santa is gearing up for the holiday season by modernizing the gift list system at his North Pole headquarters. But the elves made a mess while dipping into the eggnog and now they need you to clean it up!
A common thing you might want to be informed about is when an entry’s status is changed, but it is deceivingly hard to detect. Write a module to solve this problem in as elegant a way as possible.
There’s no time to lose, you must reverse engineer a complex formula to something that anyone can calculate, even while steering a herd of reindeer through the dark. All you have to work with is a napkin and your cunning.