Who else is doing Advent of Code 2019?

I’m using it to try to solve problems in Ruby without actually looking up syntax (looking at you, inject) and getting some practice using MiniTestinstead of RSpec which I use 99% of the time.

Day 2 was kind of fun to be able to implement a tiny virtual machine in Ruby.

Day 3 had me stumped until I just when for a naive solution in which I just created a list of all the coordinates visited instead of trying to figure out an elegant way to calculate the answer… an approach which actually paid off in the second half.

Day 4 has been the problem that I spent the most time fighting with (specifically the second part) after thinking that I had it solved. It was one of those scenarios in which I pretty much starting chasing my own tail after the solution I thought should work didn’t. I ended up with 4 state variables in addition the input variable itself.