1st commit on 042_haskell

2 files changed, 32 insertions, 0 deletions

diff --git a/challenge-042/stuart-little/haskell/ch-1.hs b/challenge-042/stuart-little/haskell/ch-1.hs
new file mode 100755
index 0000000000..937f58adde
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+++ b/challenge-042/stuart-little/haskell/ch-1.hs
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+#!/usr/bin/env runghc
+
+-- run <script>
+
+convToBase b nr
+  |nr < b =[nr]
+  |otherwise = (convToBase b high) ++ [low] where
+     (high,low) = divMod nr b
+
+main = do
+  let l = [1..50]
+  mapM_ putStrLn $ map (\(x,y) -> "Decimal: " ++ (show x) ++ " -- Octal: " ++ (concat $ map show y)) $ zip l $ map (convToBase 8) l
diff --git a/challenge-042/stuart-little/haskell/ch-2.hs b/challenge-042/stuart-little/haskell/ch-2.hs
new file mode 100755
index 0000000000..87996c398d
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+++ b/challenge-042/stuart-little/haskell/ch-2.hs
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+#!/usr/bin/env runghc
+
+-- run <script> <quoted string of parentheses or nothing; if you provide nothing a string will be generated randomly>
+
+import System.Environment (getArgs,)
+import Data.List (inits,)
+import Data.List.Extra (lastDef,headDef,)
+import System.Random (getStdGen,randomRIO,randomRs,)
+
+validate str =
+  let f '(' = 1; f ')' = -1; g x = map sum $ (map.map) f $ inits x
+  in ((lastDef 0 $ g str) == 0) && (all (0<=) $ g str)
+
+main = do
+  args <- getArgs
+  nrchars <- randomRIO (1::Int,50)
+  gen <- getStdGen  
+  let strng = headDef (take (nrchars) (randomRs ('(',')') gen)) args
+  putStrLn ("Your string: " ++ strng)
+  putStrLn $ show $ validate strng