Initial data commit

Task/Move-to-front-algorithm/Haskell/move-to-front-algorithm.hs

@@ -0,0 +1,25 @@
+import Data.List (delete, elemIndex, mapAccumL)
+
+import Data.Maybe (fromJust)
+
+table :: String
+table = ['a' .. 'z']
+
+encode :: String -> [Int]
+encode =
+  let f t s = (s : delete s t, fromJust (elemIndex s t))
+  in snd . mapAccumL f table
+
+decode :: [Int] -> String
+decode = snd . mapAccumL f table
+  where
+    f t i =
+      let s = (t !! i)
+      in (s : delete s t, s)
+
+main :: IO ()
+main =
+  mapM_ print $
+  (,) <*> uncurry ((==) . fst) <$> -- Test that ((fst . fst) x) == snd x)
+  ((,) <*> (decode . snd) <$>
+   ((,) <*> encode <$> ["broood", "bananaaa", "hiphophiphop"]))