Folks doing Advent of Code this year, share your daily solutions in #C03RR0W5DGC. Limit yourself to one top-level post per day, but use whatever tools or technology you like (doesn't need to be some experimental ML-powered accordion prototype, it can be C++, though at this point I'm not sure there's a difference). Have fun!

I've been starting a 'thread' for each day, which helps to group answers.