adventofcode/2025/README.md

Advent of Code 2025

Introduction

This is mostly so I can keep notes on my progress, in single markdown format so I can easily add it to my Silverbullet journal afterwards.

Lessons from first day

1. Read! Oh that brain of mine, skipping half the things and missing things like count clicks not end point dial
2. Setup a proper test, make a smaller input test that you know the answer to to check the code

Lessons second day

1. More git commits!
2. Clear history so you don't accidentally cp day1 to day2 during testing. (Undo FTW)
3. Put the central check (Serial Valid/Invalid) in a function so it's easy to add self checks in the beginning

Lessons third day

1. Can't win em all
2. Code is much shorter because I'm getting better with Lua, yay

Lessons fourth day

1. Need about an hour to do both, but also speeding up

Lessons fifth day

1. Lua has a maximum table size, so no brute forcing :)
2. When doing any type of comparing, a good pre-sort helps