28 lines
614 B
Elixir
28 lines
614 B
Elixir
defmodule Day5Part2 do
|
|
def run do
|
|
File.stream!("input")
|
|
|> Stream.map(&String.trim/1)
|
|
|> Stream.map(&seat_id/1)
|
|
|> Enum.sort()
|
|
|> find_seat()
|
|
|> IO.puts()
|
|
end
|
|
|
|
def find_seat([_ | next_seats] = seats) do
|
|
Stream.zip(seats, next_seats)
|
|
|> Enum.find(fn {seat, next} -> next - seat > 1 end)
|
|
|> elem(0)
|
|
|> Kernel.+(1)
|
|
end
|
|
|
|
def char_to_bit(c) when c in 'FL', do: <<0::1>>
|
|
def char_to_bit(c) when c in 'BR', do: <<1::1>>
|
|
|
|
def seat_id(boarding_pass) do
|
|
<<id::10>> = for <<char <- boarding_pass>>, into: <<>>, do: char_to_bit(char)
|
|
id
|
|
end
|
|
end
|
|
|
|
Day5Part2.run()
|