Data commit

Task/Averages-Median/Haskell/averages-median-1.hs

@@ -0,0 +1,26 @@
+import Data.List (partition)
+
+nth :: Ord t => [t] -> Int -> t
+nth (x:xs) n
+  | k == n = x
+  | k > n = nth ys n
+  | otherwise = nth zs $ n - k - 1
+  where
+    (ys, zs) = partition (< x) xs
+    k = length ys
+
+medianMay :: (Fractional a, Ord a) => [a] -> Maybe a
+medianMay xs
+  | n < 1 = Nothing
+  | even n = Just ((nth xs (div n 2) + nth xs (div n 2 - 1)) / 2.0)
+  | otherwise = Just (nth xs (div n 2))
+  where
+    n = length xs
+
+main :: IO ()
+main =
+  mapM_
+    (printMay . medianMay)
+    [[], [7], [5, 3, 4], [5, 4, 2, 3], [3, 4, 1, -8.4, 7.2, 4, 1, 1.2]]
+  where
+    printMay = maybe (putStrLn "(not defined)") print

Task/Averages-Median/Haskell/averages-median-2.hs

@@ -0,0 +1,2 @@
+> Math.Statistics.median [1,9,2,4]
+3.0