62 lines
1.6 KiB
Elixir
62 lines
1.6 KiB
Elixir
defmodule AdventOfCode.Day02 do
|
|
@moduledoc """
|
|
Day 2
|
|
"""
|
|
|
|
def parse_action("forward " <> v), do: {:forward, String.to_integer(v)}
|
|
def parse_action("down " <> v), do: {:down, String.to_integer(v)}
|
|
def parse_action("up " <> v), do: {:up, String.to_integer(v)}
|
|
end
|
|
|
|
defmodule AdventOfCode.Day02.Part1 do
|
|
@moduledoc """
|
|
Day 2, Part 1
|
|
"""
|
|
|
|
alias AdventOfCode.PuzzleSolver
|
|
use PuzzleSolver
|
|
|
|
import AdventOfCode.Day02, warn: false
|
|
|
|
@impl PuzzleSolver
|
|
def solve(input_stream) do
|
|
input_stream
|
|
|> Stream.map(&String.trim/1)
|
|
|> Stream.map(&parse_action/1)
|
|
|> Enum.reduce({0, 0}, &apply_action/2)
|
|
|> product()
|
|
end
|
|
|
|
defp apply_action({:forward, v}, {horiz, depth}), do: {horiz + v, depth}
|
|
defp apply_action({:down, v}, {horiz, depth}), do: {horiz, depth + v}
|
|
defp apply_action({:up, v}, {horiz, depth}), do: {horiz, depth - v}
|
|
|
|
defp product({x, y}), do: x * y
|
|
end
|
|
|
|
defmodule AdventOfCode.Day02.Part2 do
|
|
@moduledoc """
|
|
Day 2, Part 2
|
|
"""
|
|
|
|
alias AdventOfCode.PuzzleSolver
|
|
use PuzzleSolver
|
|
|
|
import AdventOfCode.Day02, warn: false
|
|
|
|
@impl PuzzleSolver
|
|
def solve(input_stream) do
|
|
input_stream
|
|
|> Stream.map(&String.trim/1)
|
|
|> Stream.map(&parse_action/1)
|
|
|> Enum.reduce({0, 0, 0}, &apply_action/2)
|
|
|> product()
|
|
end
|
|
|
|
defp apply_action({:forward, v}, {horiz, depth, aim}), do: {horiz + v, depth + aim * v, aim}
|
|
defp apply_action({:down, v}, {horiz, depth, aim}), do: {horiz, depth, aim + v}
|
|
defp apply_action({:up, v}, {horiz, depth, aim}), do: {horiz, depth, aim - v}
|
|
|
|
defp product({x, y, _z}), do: x * y
|
|
end
|
|
|