Advent of Code 2022 - Day 1

Mix.install([
  {:kino, "~> 0.7.0"}
])

Part 1

The puzzle input is calorie totals separated by two newlines.

For part 1 we are to find the largest calorie total from the given groups.

sample_input = """
1000
2000
3000

4000

5000
6000

7000
8000
9000

10000
"""

sample_result =
  sample_input
  |> String.split("\n\n")
  |> Enum.map(&String.split(&1, "\n", trim: true))
  |> Enum.map(fn carrying ->
    Enum.map(carrying, &String.to_integer/1)
  end)
  |> Enum.map(&Enum.sum/1)
  |> Enum.max()

defmodule Day1.Part1 do
  def max_calories(input) when is_binary(input) do
    input
    |> String.split("\n\n")
    |> Enum.map(&String.split(&1, "\n"))
    |> Enum.map(fn carrying ->
      Enum.map(carrying, &String.to_integer/1)
    end)
    |> Enum.map(&Enum.sum/1)
    |> Enum.max()
  end

  def max_calories(input) do
    input
    |> Kino.Input.read()
    |> max_calories()
  end
end

day1_input = Kino.Input.textarea("Please paste the day 1 input")

Day1.Part1.max_calories(day1_input)

Part 2

For part 2 we are to find the sum of the three largest calorie totals from the given groups.

defmodule Day1.Part2 do
  def sum_calories(input, opts \\ [])

  def sum_calories(input, opts) when is_map(input) do
    input
    |> Kino.Input.read()
    |> sum_calories(opts)
  end

  def sum_calories(input, top: count) do
    input
    |> sum_input_groups()
    |> Enum.sort(:desc)
    |> Enum.take(count)
    |> Enum.sum()
  end

  def sum_calories(input, bottom: count) do
    input
    |> sum_input_groups()
    |> Enum.sort(:asc)
    |> Enum.take(count)
    |> Enum.sum()
  end

  defp sum_input_groups(input) do
    input
    |> String.split("\n\n")
    |> Enum.map(&String.split(&1, "\n"))
    |> Enum.map(fn carrying ->
      Enum.map(carrying, &String.to_integer/1)
    end)
    |> Enum.map(&Enum.sum/1)
  end
end

Day1.Part2.sum_calories(day1_input, top: 3)