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Diffstat (limited to 'racket/aoc2021/day-02/day-02.ex')
-rw-r--r-- | racket/aoc2021/day-02/day-02.ex | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/racket/aoc2021/day-02/day-02.ex b/racket/aoc2021/day-02/day-02.ex new file mode 100644 index 0000000..d37ab05 --- /dev/null +++ b/racket/aoc2021/day-02/day-02.ex @@ -0,0 +1,32 @@ +defmodule Day02 do + def part_one(data) do + data + |> Enum.reduce(%{pos: 0, dep: 0}, &method_one/2) + |> get_answer() + end + + def part_two(data) do + data + |> Enum.reduce(%{pos: 0, dep: 0, aim: 0}, &method_two/2) + |> get_answer() + end + + defp method_one({:forward, x}, s), do: %{s | pos: s.pos + x} + defp method_one({:up, x}, s), do: %{s | dep: s.dep - x} + defp method_one({:down, x}, s), do: %{s | dep: s.dep + x} + + defp method_two({:forward, x}, s), do: %{s | pos: s.pos + x, dep: s.dep + s.aim * x} + defp method_two({:up, x}, s), do: %{s | aim: s.aim - x} + defp method_two({:down, x}, s), do: %{s | aim: s.aim + x} + + defp get_answer(s), do: s.pos * s.dep +end + +data = + File.read!("day-02/input.txt") + |> String.split("\n", trim: true) + |> Enum.map(&String.split/1) + |> Enum.map(fn [dir, amt] -> {String.to_atom(dir), String.to_integer(amt)} end) + +Day02.part_one(data) |> IO.inspect() +Day02.part_two(data) |> IO.inspect() |