As a warmup for this year’s Advent of Code, I’m re-reading and posting my solutions to last year’s challenges. You can read, run and edit today’s solution by following the post link.

I remember really enjoying this challenge. We were asked to determine visibility across a grid of variable height trees, first looking in, then looking out. What was easy to describe turned out to be quite tricky to implement (for me at least!). As so many AOC problems involve navigating around grids, I had a handy Grid class availalble to help me. Perhaps a bit OTT for this use, but when you have a hammer…