Day 3: Mull It Over
Megathread guidelines
- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL
FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
Elixir
First time writing Elixir. It’s probably janky af.
I’ve had some help from AI to get some pointers along the way. I’m not competing in any way, just trying to learn and have fun.
~~Part 2 is currently not working, and I can’t figure out why. I’m trying to just remove everything from “don’t()” to “do()” and just pass the rest through the working solution for part 1. Should work, right?
Any pointers?~~
edit; working solution:
defmodule Three do def get_input do File.read!("./input.txt") end def extract_operations(input) do Regex.scan(~r/mul\((\d{1,3}),(\d{1,3})\)/, input) |> Enum.map(fn [_op, num1, num2] -> num1 = String.to_integer(num1) num2 = String.to_integer(num2) [num1 * num2] end) end def sum_products(ops) do List.flatten(ops) |> Enum.filter(fn x -> is_integer(x) end) |> Enum.sum() end def part1 do extract_operations(get_input()) |> sum_products() end def part2 do String.split(get_input(), ~r/don\'t\(\)[\s\S]*?do\(\)/) |> Enum.map(&extract_operations/1) |> sum_products() end end IO.puts("part 1: #{Three.part1()}") IO.puts("part 2: #{Three.part2()}")
I think I had the same issue. Consider what happens if there isn’t a do() after a don’t().
Ah, yes, that’s it. The lazy solution would be to add a “do()” to the end of the input, right? Haha
It was actually a line break that broke the regex. Changing from a “.” to “[\s\S]” fixed it.