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@ -4,10 +4,12 @@ module Day2 (day2) where |
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import qualified Data.Text as T |
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import qualified Data.Text as T |
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import qualified Data.Attoparsec.Text as P |
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import qualified Data.Attoparsec.Text as P |
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import Data.List (elemIndices) |
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type Max = Int |
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type Max = Int |
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type Min = Int |
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type Min = Int |
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type Letter = Char |
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type Letter = Char |
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type Validator = Policy -> String -> Bool |
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data Policy = Policy { lBound :: Min |
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data Policy = Policy { lBound :: Min |
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, uBound :: Max |
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, uBound :: Max |
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@ -24,20 +26,34 @@ parserPolicy = do |
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_ <- P.string ": " |
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_ <- P.string ": " |
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return $ Policy lB uB le |
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return $ Policy lB uB le |
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validatePolicy :: Policy -> String -> Bool |
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validatePolicy :: Validator |
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validatePolicy p s = |
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validatePolicy p s = |
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let l = length $ filter (== letter p) s in |
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let l = length $ filter (== letter p) s in |
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l >= lBound p && l <= uBound p |
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l >= lBound p && l <= uBound p |
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validateLine :: String -> Bool |
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validateLine :: Validator -> String -> Bool |
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validateLine s = |
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validateLine v s = |
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case P.parse parserPolicy (T.pack s) of |
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case P.parse parserPolicy (T.pack s) of |
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P.Fail {} -> error "day2 - parser error" |
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P.Fail {} -> error "day2 - parser error" |
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P.Partial _ -> error "day2 - input error" |
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P.Partial _ -> error "day2 - input error" |
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P.Done i r -> validatePolicy r (T.unpack i) |
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P.Done i r -> v r (T.unpack i) |
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xor :: Bool -> Bool -> Bool |
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xor True = not |
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xor False = id |
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validateCorrectPolicy :: Validator |
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validateCorrectPolicy p s = |
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let index1 = lBound p - 1 |
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index2 = uBound p - 1 |
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indices = elemIndices (letter p) s in |
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xor (index1 `elem` indices) (index2 `elem` indices) |
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day2 :: IO () |
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day2 :: IO () |
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day2 = do |
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day2 = do |
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r <- readFile "./input/day2" |
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rs <- lines <$> readFile "./input/day2" |
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putStr "[Day 2-1] # valid passwords: " |
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putStr "[Day 2-1] # valid passwords: " |
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print . length . filter (==True) . fmap validateLine . lines $ r |
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print . length . filter (==True) . fmap (validateLine validatePolicy) $ rs |
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putStr "[Day 2-2] # valid passwords: " |
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print . length . filter (==True) . fmap (validateLine validateCorrectPolicy) $ rs |
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