Files
aoc-2023/lib/day7.ex
2023-12-07 12:12:31 +00:00

67 lines
1.3 KiB
Elixir

defmodule Aoc2023.Day7 do
use Aoc2023
def hand_type(values) do
values
|> Enum.frequencies()
|> then(fn freq ->
{jokers, freq_} = freq |> Map.pop(0, 0)
common = freq_ |> Enum.max_by(pipe(elem(1))) |> elem(0)
freq_ |> Map.update!(common, &(&1 + jokers))
end)
|> Enum.map(pipe(elem(1)))
|> Enum.sort(:desc)
|> case do
[5] -> 6
[4, 1] -> 5
[3, 2] -> 4
[3, 1, 1] -> 3
[2, 2, 1] -> 2
[2, 1, 1, 1] -> 1
[1, 1, 1, 1, 1] -> 0
end
end
def parse(input) do
fn rankings ->
input
|> lines
|> Enum.map(&String.split/1)
|> Enum.map(fn [hand, bid] ->
{
hand |> String.to_charlist() |> Enum.map(&Map.get(rankings, &1)),
bid |> String.to_integer()
}
end)
|> Enum.sort_by(elem(0) |> hand_type &&& elem(0), :asc)
|> Enum.with_index(1)
|> Enum.map(fn {{_, bid}, index} -> bid * index end)
|> Enum.sum()
end
end
@ranking %{
?A => 13,
?K => 12,
?Q => 11,
?J => 10,
?T => 9,
?9 => 8,
?8 => 7,
?7 => 6,
?6 => 5,
?5 => 4,
?4 => 3,
?3 => 2,
?2 => 1
}
def part1(input) do
input.(@ranking)
end
def part2(input) do
input.(@ranking |> Map.put(?J, 0))
end
end