Day12

Setup

Mix.install(
  [
    {:kino, "~> 0.4.1"}
  ],
  consolidate_protocols: false
)

input = Kino.Input.textarea("Please paste your input:")

# start-A
# start-b
# A-c
# A-b
# b-d
# A-end
# b-end

%{
  start: ['A', 'b'],
  A: ['c', 'b', 'end', 'start'],
  b: ['d', 'end', 'start', 'A'],
  c: ['A'],
  d: ['b'],
  end: ['A', 'b']
}

# start, A,
# start, A, c
# start, A, c, A
# start, A, c, A, b
# start, A, c, A, b, end
# start, A, c, A, b, A
# start, A, c, A, b, A, end
# start, A, c, A, end
# start, A, b
# start, A, b, end
# start, A, b, A
# start, A, b, A, c
# start, A, b, A, c, A, end
# start, A, b, A, end
# start, A, end
# start, b,
# start, b, end
# start, b, A
# start, b, A, c
# start, b, A, c, A
# start, b, A, c, end
# start, b, A, end

lines =
  input
  |> Kino.Input.read()
  |> String.split(["\n"], trim: true)
  # |> Enum.map(fn line -> String.split(line, "-")end)
  |> Enum.reduce(%{}, fn line, map ->
    [left, right] = String.split(line, "-")

    map
    |> Map.update(left, MapSet.new([right]), &MapSet.put(&1, right))
    |> Map.update(right, MapSet.new([left]), &MapSet.put(&1, left))
  end)

Part 1

defmodule Recursion do
  def crawl(_map, _position, path = ['end' | _tail], paths) do
    [path | paths]
  end

  def crawl(cave) do
    crawl(cave, "start", ["start"], [])
  end

  def crawl(cave, position, path, paths) do
    cave[position]
    |> Enum.reduce([], fn pos, paths ->
      crawl(cave, pos, [pos | path], paths)
    end)
  end
end

# [head | tail] = ['a' | ['x', 'y']]
# head

Part 2