19 lines
775 B
Haskell
19 lines
775 B
Haskell
import Data.Char
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import Data.List.Split
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import Data.List
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main :: IO ()
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main = do
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input_raw <- map (map digitToInt) <$> lines <$> readFile "day09/input"
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let nines = take (length (head input_raw)) $ repeat 9
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let nineIt x = map ((9:) . (++[9])) $ (nines : x ++ [nines])
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print $ day09 (nineIt input_raw) input_raw
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day09 :: [[Int]] -> [[Int]] -> Int
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day09 input input_raw = foldl (\acc (x,y) ->if y then acc+1+x else acc) 0 $ zip (concat input_raw) bools
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where vert = tail $ init $ map ((map isSmol) . divvy 3 1) (transpose input)
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horz = tail $ init $ map ((map isSmol) . divvy 3 1) input
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isSmol [a,b,c] = if b<a && b<c then True else False
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isSmol :: [Int] -> Bool
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bools = zipWith (&&) (concat (transpose vert)) (concat horz)
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