Advent Of Code 2022 Day 1

Mix.install([
  {:req, "~> 0.3.2"}
])

Section

defmodule Load do
  @aoc_session System.fetch_env!("LB_AOC_SESSION")

  def input() do
    {:ok, %{body: input_raw}} =
      Req.get(
        "https://adventofcode.com/2022/day/1/input",
        headers: [cookie: "session=#{@aoc_session}"]
      )

    input_raw
  end
end

defmodule Part1 do
  @input Load.input()

  def solve(input \\ @input) do
    input
    |> String.split("\n\n", trim: true)
    |> Enum.map(&elf_line_to_total_calories/1)
    |> Enum.max()
  end

  defp elf_line_to_total_calories(line) do
    line
    |> String.split("\n", trim: true)
    |> Enum.map(&String.to_integer/1)
    |> Enum.sum()
  end
end

Part1.solve()

defmodule Part2 do
  @input Load.input()

  def solve(input \\ @input) do
    input
    |> String.split("\n\n", trim: true)
    |> Enum.map(&elf_line_to_total_calories/1)
    |> Enum.sort(fn a, b -> b < a end)
    |> Enum.take(3)
    |> Enum.sum()
  end

  defp elf_line_to_total_calories(line) do
    line
    |> String.split("\n", trim: true)
    |> Enum.map(&String.to_integer/1)
    |> Enum.sum()
  end
end

Part2.solve()

ExUnit.start(autorun: false)

defmodule Test do
  use ExUnit.Case, async: true

  test "part1" do
    assert Part1.solve() == 72511
  end

  test "part2" do
    assert Part2.solve() == 212_117
  end
end

ExUnit.run()