Files
book-exercises/Haskell-book/11/Cipher.hs
2025-12-09 16:32:32 +01:00

25 lines
611 B
Haskell

module Cipher where
import Data.Char
import Data.List
decode :: (Char, Int) -> Char
decode (x, y) = chr ((mod ((ord x) - 65 + y) 26) + 65)
decodeWithKey :: [Int] -> String -> String
decodeWithKey _ [] = []
decodeWithKey ys (' ':xs) = ' ' : (decodeWithKey ys xs)
decodeWithKey (y:ys) (x:xs) = (decode (x, y)) : (decodeWithKey ys xs)
vigenere :: String -> String
vigenere = decodeWithKey (cycle [0, 11, 11, 24])
caeser :: String -> String
caeser = decodeWithKey (cycle [11])
main :: IO ()
main = do
putStrLn (vigenere "MEET AT DAWN")
putStrLn (caeser "MEET AT DAWN")
return ()