Hello! Advent of Year 2023 is upon us and like past few years, I’ll be opening threads discussing each year’s problems.

Day 1 was today. This was a rather interesting challenge for a day 1. Not as easy as others and the puzzle came with some sneaky edge cases. But regular expressions ftw!

Also this is the first time I am using Scala (or any other language than Elixir) to solve it. While I did not know how to deal with lookahead on Scala Regex (shame on me), I did quite a nifty trick. Then I went ahead and did Elixir too.

Scala Version

advent-of-scala/src/main/scala/advent_of_scala/2023/Day01.scala at main · code-shoily/advent-of-scala (github.com)

Elixir Version

advent_of_code/lib/2023/day_01.ex at master · code-shoily/advent_of_code (github.com)

There is an interesting difference - Scala one uses two regex patterns (one inverse of the other) while Elixir uses the simpler lookahead regex. I blame my lack of Scala library knowledge here.

See on around Day 2.