Day 4 of Advent of Code done with Typescript. Lessons learned:

1. console.log() is super slow, I thought a recursive function was blocked, but it was just really slow. I took out the logging and it came back in a few seconds
2. typescript has "sets" but they don't have a built in way to do intersections... I know an array of unique values can be useful for the uniqueness, but comparisons are a pretty valuable part of sets.
3. I still hate typescript and I refuse to learn the difference between var and let until it bites me