These are solutions originally written in 2018 for the Advent of Code challenge. Whilst it is an improvement on my 2017 work, the solutions are messy and poorly structured (and there are very few comments).
A better structure for how to run this challenge can be found in my 2021 AOC repository. The solutions are still not polished in here, but the structure and helper functions are better designed.
Rather than go back and make these look neat and polished, I like to be able to reflect on where I started, and the improvements that I have made over the years.