2023 - day 6

Mix.install([
  {:kino, "~> 0.11.3"}
])

Section

input = Kino.Input.textarea("input")

input = Kino.Input.read(input)

sample_input = """
Time:      7  15   30
Distance:  9  40  200
"""

Part 1

defmodule Day6 do
  defmodule Part1 do
    def solve(input_str) do
      input_str
      |> Day6.parse()
      |> do_solve()
    end

    defp do_solve(pairs) do
      pairs
      |> Enum.map(&count_record/1)
      |> Enum.product()
    end

    def count_record({time, distance}) do
      for t <- 1..(time - 1), (time - t) * t > distance, reduce: 0 do
        acc -> acc + 1
      end
    end
  end

  defmodule Part2 do
    def solve(input_str) do
      input_str
      |> Day6.parse2()
      |> Day6.Part1.count_record()
    end
  end

  def parse(input_str) do
    ["Time:" <> times, "Distance:" <> distances] = input_str |> String.split("\n", trim: true)
    time_list = times |> String.split(" ", trim: true) |> Enum.map(&amp;String.to_integer/1)
    distance_list = distances |> String.split(" ", trim: true) |> Enum.map(&amp;String.to_integer/1)
    Enum.zip(time_list, distance_list)
  end

  def parse2(input_str) do
    ["Time:" <> times, "Distance:" <> distances] = input_str |> String.split("\n", trim: true)
    time = times |> String.replace("\s", "") |> String.to_integer()
    distance = distances |> String.replace("\s", "") |> String.to_integer()
    {time, distance}
  end
end

Day6.Part1.solve(input)

Day6.Part2.solve(input)