44 lines
1.2 KiB
Haskell
44 lines
1.2 KiB
Haskell
module Main where
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import Data.Char
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import Data.Foldable (toList)
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import Data.Function (on)
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import Data.List (minimumBy)
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import qualified Data.Sequence as S
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import Data.Sequence ((><), (|>))
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xor :: Bool -> Bool -> Bool
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xor True False = True
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xor False True = True
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xor _ _ = False
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isReactive :: Char -> Char -> Bool
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isReactive x y = toLower x == toLower y && (isUpper x `xor` isUpper y)
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simplify :: S.Seq Char -> S.Seq Char -> S.Seq Char
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simplify acc s
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| S.null s = acc
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| S.length s == 1 = acc >< s
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| S.length s >= 2 =
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let [x,y] = toList (S.take 2 s)
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in if isReactive x y
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then simplify acc (S.drop 2 s)
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else simplify (acc |> x) (S.drop 1 s)
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collapse :: S.Seq Char -> S.Seq Char
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collapse s =
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let simplified = simplify S.empty s
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in if S.length simplified == S.length s
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then s
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else collapse simplified
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betterCollapse :: S.Seq Char -> S.Seq Char
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betterCollapse s =
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minimumBy (compare `on` S.length)
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. map (\c -> collapse $ S.filter (\c' -> toLower c' /= toLower c) s)
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$ ['a' .. 'z']
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main = do
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input <- S.fromList . filter (/= '\n') <$> getContents
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putStrLn $ "Size = " ++ show (S.length $ collapse input)
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putStrLn $ "Better Size = " ++ show (S.length $ betterCollapse (collapse input)) |