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  • 19 Comments
Joined 7 months ago
Cake day: May 28th, 2024
  • rwdf@lemmy.worldtoAdvent Of Code@programming.dev•🌲 - 2024 DAY 1 SOLUTIONS -🌲
    1·
    12 days ago

    Elixir

    Total noob, but it’s fun to learn.

    {left, right} =
  File.read!("./input.txt")
  |> String.split("\n", trim: true)
  |> Enum.map(fn line ->
    String.split(line)
    |> Enum.map(&String.to_integer/1)
    |> List.to_tuple()
  end)
  |> Enum.unzip()
  |> then(fn {left, right} ->
    {Enum.sort(left), Enum.sort(right)}
  end)

diffs =
  Enum.zip(left, right)
  |> Enum.map(fn {l, r} -> abs(l - r) end)
  |> Enum.sum()

freqs =
  Enum.filter(right, fn r -> r in left end)
  |> Enum.frequencies()

freqsum =
  Enum.map(left, fn n ->
    freq = Map.get(freqs, n, 0)
    n * freq
  end)
  |> Enum.sum()

IO.puts("part 1: #{diffs}")
IO.puts("part 2: #{freqsum}")
  • rwdf@lemmy.worldtoAdvent Of Code@programming.dev•🌲 - 2024 DAY 1 SOLUTIONS -🌲
    2·
    12 days ago

    Go

    package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
	"strings"
)

func main() {
	input, _ := os.Open("input.txt")
	defer input.Close()

	left, right := []int{}, []int{}

	scanner := bufio.NewScanner(input)
	for scanner.Scan() {
		line := scanner.Text()
		splitline := strings.Split(line, "   ")
		l, _ := strconv.Atoi(splitline[0])
		r, _ := strconv.Atoi(splitline[1])
		left, right = append(left, l), append(right, r)
	}

	fmt.Printf("part 1 - total diff: %d\n", part1(left, right))
	fmt.Printf("part 2 - new total: %d\n", part2(left, right))
}

func part1(left, right []int) int {
	diff := 0
	sort.Ints(left)
	sort.Ints(right)

	for i, l := range left {
		if l > right[i] {
			diff += (l - right[i])
		} else {
			diff += (right[i] - l)
		}
	}
	return diff
}

func part2(left, right []int) int {
	newTotal := 0

	for _, l := range left {
		matches := 0
		for _, r := range right {
			if l == r {
				matches++
			}
		}
		newTotal += l * matches
	}
	return newTotal
}
  • rwdf@lemmy.worldtoAdvent Of Code@programming.dev•🍷 - 2024 DAY 3 SOLUTIONS -🍷
    2·
    12 days ago

    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()}")