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