15 lines
390 B
Haskell
15 lines
390 B
Haskell
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import Data.List.Split (splitOn)
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lineSafe :: [Int] -> Bool
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lineSafe [] = True
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lineSafe l@(_:xs) = (all (> 0) diffs || all (< 0) diffs) && all validItem diffs
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where
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diffs = zipWith (-) xs l
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validItem x = x /= 0 && abs x <= 3
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main :: IO ()
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main = print . length . filter testLine . lines =<< readFile "data.txt"
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where
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testLine = lineSafe . map read . splitOn " "
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