19 lines
770 B
Haskell
19 lines
770 B
Haskell
module Part2 where
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import Commons
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import Data.Set (empty, map, toList, delete)
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import Data.Array (bounds)
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getEnergized :: (Int, Int, Direction) -> Cavern -> [(Int, Int)]
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getEnergized (y0, x0, d) = toList . delete (y0, x0) . Data.Set.map (\ (y, x, _) -> (y, x)) . lightBeam (y0, x0) d empty
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getStarts :: Cavern -> [(Int, Int, Direction)]
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getStarts c = [(y, 0, East) | y <- [1..fst (snd $ bounds c)]]
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++ [(y, 1 + snd (snd $ bounds c), West) | y <- [1..fst (snd $ bounds c)]]
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++ [(0, x, South) | x <- [1..snd (snd $ bounds c)]]
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++ [(1 + fst (snd $ bounds c), x, North) | x <- [1..snd (snd $ bounds c)]]
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getMaxEnergized :: Cavern -> Int
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getMaxEnergized c = maximum (Prelude.map (\s -> length $ getEnergized s c) $ getStarts c)
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