Advent of Code 2023 Day 6

Section

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

defmodule Race do
  def process_numbers(row, joined \\ false) do
    numbers = String.split(row, ~r/\s+/, trim: true)

    if joined do
      [String.to_integer(Enum.join(numbers))]
    else
      Enum.map(numbers, &String.to_integer/1)
    end
  end

  def parse(input, joined \\ false) do
    input
    |> String.split("\n", trim: true)
    |> Enum.map(fn row -> Enum.at(String.split(row, ":", trim: true), 1) end)
    |> Enum.map(fn row -> process_numbers(row, joined) end)
    |> Enum.zip()
  end

  def race(input, joined \\ false) do
    parse(input, joined)
    |> Enum.map(fn {duration, distance} ->
      Enum.filter(
        Enum.map(Range.new(1, duration - 1), fn attempt -> (duration - attempt) * attempt end),
        fn attempt -> attempt > distance end
      )
    end)
    |> Enum.map(&Enum.count/1)
    |> Enum.product()
  end
end

Race.parse(input)

Race.race(input)

full_input = """
Time:        48     93     85     95
Distance:   296   1928   1236   1391
"""

Race.race(full_input)

new_input = """
Time:      71530
Distance:  940200
"""

Race.race(new_input)

Race.race(input, true)

Race.race(full_input, true)