Initial data commit

Task/Semordnilap/Haskell/semordnilap.hs

@@ -0,0 +1,17 @@
+import qualified Data.Set as S
+
+semordnilaps
+  :: (Ord a, Foldable t)
+  => t [a] -> [[a]]
+semordnilaps =
+  let f x (s, w)
+        | S.member (reverse x) s = (s, x : w)
+        | otherwise = (S.insert x s, w)
+  in snd . foldr f (S.empty, [])
+
+main :: IO ()
+main = do
+  s <- readFile "unixdict.txt"
+  let l = semordnilaps (lines s)
+  print $ length l
+  mapM_ (print . ((,) <*> reverse)) $ take 5 (filter ((4 <) . length) l)