I started learning Haskell very recently, and I just learned this year that [Advent of Code](https://adventofcode.com 'Advent of Code website') is a thing, so I used AoC to practice Haskell. I got 38 out of 50 stars, which is more than I though I could get, so I'm quite satisfied. Solutions are not optimal, but most of them run in less than a second, while there are a few that take longer than a minute.