tasks a-s

Task/Semordnilap/Haskell/semordnilap.hs

@@ -0,0 +1,10 @@
+import qualified Data.Set as S
+
+semordnilaps = snd . foldl f (S.empty,[]) where
+	f (s,w) x | S.member (reverse x) s = (s, x:w)
+	          | otherwise = (S.insert x s, w)
+
+main=do	s <- readFile "unixdict.txt"
+	let l = semordnilaps (lines s)
+	print $ length l
+	mapM_ print $ map (\x->(x, reverse x)) $ take 5 l