36 lines
962 B
Haskell
36 lines
962 B
Haskell
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#!/usr/bin/env runghc
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import Data.Char
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data PasswordEntry = PasswordEntry { min :: Int, max :: Int, character :: Char, password :: String }
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deriving (Show)
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-- This could be a lot better...
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instance Read PasswordEntry where
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readsPrec _ input =
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let (min', rest) = span isDigit input
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min = read min' :: Int
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(_, rest') = splitAt 1 rest
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(max', rest'') = span isDigit rest'
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max = read max' :: Int
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(_:char:_:_:password) = rest''
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in
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[(PasswordEntry min max char password, "")]
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main = interact solve
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solve = show . length . filter (isValidPasswordEntry . readPasswordEntry) . lines
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readPasswordEntry :: String -> PasswordEntry
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readPasswordEntry = read
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isValidPasswordEntry (PasswordEntry min max char pass) =
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let countedElem = countElem char pass
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in min <= countedElem && max >= countedElem
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countElem _ [] = 0
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countElem a (x:xs)
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| a == x = 1 + countElem a xs
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countElem a (_:xs) = countElem a xs
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