80 lines
1.9 KiB
Elixir
80 lines
1.9 KiB
Elixir
|
#!/usr/bin/env elixir
|
||
|
|
defmodule Day2 do
|
||
|
|
def part1(input) do
|
||
|
|
input
|
||
|
|
|> Map.filter(fn {_id, cubes} ->
|
||
|
|
cubes["red"] <= 12 and cubes["green"] <= 13 and cubes["blue"] <= 14
|
||
|
|
end)
|
||
|
|
|> Map.keys()
|
||
|
|
|> Enum.sum()
|
||
|
|
end
|
||
|
|
|
||
|
|
def part2(input) do
|
||
|
|
input
|
||
|
|
|> Enum.map(fn {_id, cubes} -> cubes |> Map.values() |> Enum.product() end)
|
||
|
|
|> Enum.sum()
|
||
|
|
end
|
||
|
|
|
||
|
|
def input do
|
||
|
|
with [input_filename] <- System.argv(),
|
||
|
|
{:ok, input} <- File.read(input_filename) do
|
||
|
|
input
|
||
|
|
|> String.split("\n", trim: true)
|
||
|
|
|> Map.new(fn line ->
|
||
|
|
["Game " <> id | rounds] = String.split(line, [": ", "; "])
|
||
|
|
|
||
|
|
rounds =
|
||
|
|
rounds
|
||
|
|
|> Enum.map(&parse_round/1)
|
||
|
|
|> Enum.reduce(
|
||
|
|
%{"red" => 0, "green" => 0, "blue" => 0},
|
||
|
|
&Map.merge(&1, &2, fn _colour, count1, count2 -> max(count1, count2) end)
|
||
|
|
)
|
||
|
|
|
||
|
|
{String.to_integer(id), rounds}
|
||
|
|
end)
|
||
|
|
else
|
||
|
|
_ -> :error
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
def parse_round(round) do
|
||
|
|
round
|
||
|
|
|> String.split([", ", " "])
|
||
|
|
|> Enum.chunk_every(2)
|
||
|
|
|> Map.new(fn [number, colour] -> {colour, String.to_integer(number)} end)
|
||
|
|
end
|
||
|
|
|
||
|
|
#######################
|
||
|
|
# HERE BE BOILERPLATE #
|
||
|
|
#######################
|
||
|
|
|
||
|
|
def run do
|
||
|
|
case input() do
|
||
|
|
:error -> print_usage()
|
||
|
|
input -> run_parts_with_timer(input)
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
defp run_parts_with_timer(input) do
|
||
|
|
run_with_timer(1, fn -> part1(input) end)
|
||
|
|
run_with_timer(2, fn -> part2(input) end)
|
||
|
|
end
|
||
|
|
|
||
|
|
defp run_with_timer(part, fun) do
|
||
|
|
{time, result} = :timer.tc(fun)
|
||
|
|
IO.puts("Part #{part} (completed in #{format_time(time)}):\n")
|
||
|
|
IO.puts("#{inspect(result)}\n")
|
||
|
|
end
|
||
|
|
|
||
|
|
defp format_time(μsec) when μsec < 1_000, do: "#{μsec}μs"
|
||
|
|
defp format_time(μsec) when μsec < 1_000_000, do: "#{μsec / 1000}ms"
|
||
|
|
defp format_time(μsec), do: "#{μsec / 1_000_000}s"
|
||
|
|
|
||
|
|
defp print_usage do
|
||
|
|
IO.puts("Usage: elixir day2.exs input_filename")
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
Day2.run()
|