2016 Update

Task/Sorting-algorithms-Counting-sort/Elixir/sorting-algorithms-counting-sort.elixir

@@ -1,24 +1,14 @@
 defmodule Sort do
   def counting_sort([]), do: []
   def counting_sort(list) do
-    {min, max} = minmax(list)
-    count = List.to_tuple(for _ <- min..max, do: 0)
+    {min, max} = Enum.min_max(list)
+    count = Tuple.duplicate(0, max - min + 1)
     counted = Enum.reduce(list, count, fn x,acc ->
       i = x - min
       put_elem(acc, i, elem(acc, i) + 1)
     end)
-    Enum.reduce(max..min, [], fn n,acc ->
-      m = elem(counted, n - min)
-      List.duplicate(n, m) ++ acc
-    end)
+    Enum.flat_map(min..max, &List.duplicate(&1, elem(counted, &1 - min)))
   end
-
-  defp minmax([h|t]), do: minmax(t, h, h)
-
-  defp minmax([], min, max), do: {min, max}
-  defp minmax([h|t], min, max) when h<min, do: minmax(t, h, max)
-  defp minmax([h|t], min, max) when max<h, do: minmax(t, min, h)
-  defp minmax([_|t], min, max)           , do: minmax(t, min, max)
 end
 
 IO.inspect Sort.counting_sort([1,-2,-3,2,1,-5,5,5,4,5,9])