28 lines
874 B
Haskell
28 lines
874 B
Haskell
import Control.Arrow
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import Data.List
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main :: IO ()
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main = interact $ show . day12 . map parse . lines
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parse :: String -> (String, [Int])
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parse = second (read . ('[' :) . (++ "]") . tail) . break (== ' ')
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day12 :: [(String, [Int])] -> Int
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day12 = sum . map (uncurry (countArr 0))
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part2ify :: (String, [Int]) -> (String, [Int])
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part2ify (s, xs) = (intercalate "?" $ replicate 5 s, concat $ replicate 5 xs)
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countArr :: Int -> String -> [Int] -> Int
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countArr 0 [] [] = 1
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countArr _ [] [] = 0
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countArr _ ss [] = fromEnum $ not $ any (=='#') ss
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countArr streak [] [i] = fromEnum $ streak==i
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countArr streak (s:ss) (i:is)
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| s=='.' && streak == 0 = countArr 0 ss (i:is)
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| s=='.' && streak == i = countArr 0 ss is
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| s=='.' = 0
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| s=='#' = countArr (succ streak) ss (i:is)
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| s=='?' = countArr streak ('.':ss) (i:is) + countArr streak ('#':ss) (i:is)
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countArr _ _ _ = 0
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