Another update from ingydotnet^djgoku

Task/Entropy/Elixir/entropy.elixir

@@ -0,0 +1,14 @@
+defmodule RC do
+  def entropy(str) do
+    leng = String.length(str)
+    String.split(str, "", trim: true)
+    |> Enum.group_by(&(&1))
+    |> Enum.map(fn{_,value} -> length(value) end)
+    |> Enum.reduce(0, fn count, entropy ->
+         freq = count / leng
+         entropy - freq * :math.log2(freq)
+       end)
+  end
+end
+
+IO.inspect RC.entropy("1223334444")