diff options
| -rwxr-xr-x | challenge-114/stuart-little/haskell/ch-1.hs | 22 | ||||
| -rwxr-xr-x | challenge-114/stuart-little/haskell/ch-2.hs | 20 |
2 files changed, 42 insertions, 0 deletions
diff --git a/challenge-114/stuart-little/haskell/ch-1.hs b/challenge-114/stuart-little/haskell/ch-1.hs new file mode 100755 index 0000000000..e73af3b7b8 --- /dev/null +++ b/challenge-114/stuart-little/haskell/ch-1.hs @@ -0,0 +1,22 @@ +#!/usr/bin/env runghc + +-- run <script> <number> + +import System.Environment (getArgs) + +doubleUp :: Int -> String -> String +doubleUp nrDigs initHalf = initHalf ++ otherHalf where + otherHalf = if (odd nrDigs) then (reverse . init $ initHalf) else (reverse initHalf) + +nxtPali :: String -> String +nxtPali nrStr + |nr <= 8 = show (nr + 1) + |null $ dropWhile ('9'==) nrStr = show (nr + 2) + |otherwise = if pali > nr then show pali else (doubleUp nrDigs . show . (1+) . (read::String->Int) $ initHalf) where + nrDigs = length nrStr + initHalf = take (div (nrDigs+1) 2) nrStr + pali = (read::String->Int) $ doubleUp nrDigs initHalf + nr = (read::String->Int) nrStr + +main :: IO () +main = getArgs >>= putStrLn . nxtPali . head diff --git a/challenge-114/stuart-little/haskell/ch-2.hs b/challenge-114/stuart-little/haskell/ch-2.hs new file mode 100755 index 0000000000..0d8a230340 --- /dev/null +++ b/challenge-114/stuart-little/haskell/ch-2.hs @@ -0,0 +1,20 @@ +#!/usr/bin/env runghc + +-- run <script> + +import Data.Char (digitToInt) +import Data.Digits (digits,unDigits) +import System.Environment (getArgs) +import Text.RegexPR (subRegexPR) + +nxtSameNrBits :: String -> String +nxtSameNrBits binNr = if (last binNr == '1') + then subRegexPR "01(1*)$" "10\\1" binNr + else subRegexPR "01(1*)(0*)$" "10\\2\\1" binNr + +main = do + binNr <- getArgs >>= return . concat . map show . (0:) . (digits 2) . (read::String->Int) . head + putStrLn $ "Initial number in base two: " ++ binNr + let nxt = nxtSameNrBits binNr + putStrLn $ "Next number in base two: " ++ nxt + putStrLn $ "Next number in base ten: " ++ (show . unDigits 2 . map digitToInt $ nxt) |
