Data commit

Task/Move-to-front-algorithm/Elixir/move-to-front-algorithm.elixir

@@ -0,0 +1,26 @@
+defmodule MoveToFront do
+  @table  Enum.to_list(?a..?z)
+
+  def encode(text), do: encode(to_char_list(text), @table, [])
+
+  defp encode([], _, output), do: Enum.reverse(output)
+  defp encode([h|t], table, output) do
+    i = Enum.find_index(table, &(&1 == h))
+    encode(t, move2front(table, i), [i | output])
+  end
+
+  def decode(indices), do: decode(indices, @table, [])
+
+  defp decode([], _, output), do: Enum.reverse(output) |> to_string
+  defp decode([h|t], table, output) do
+    decode(t, move2front(table, h), [Enum.at(table, h) | output])
+  end
+
+  def move2front(table, i), do: [Enum.at(table,i) | List.delete_at(table, i)]
+end
+
+Enum.each(["broood", "bananaaa", "hiphophiphop"], fn word ->
+  IO.inspect word
+  IO.inspect enc = MoveToFront.encode(word)
+  IO.puts "#{word == MoveToFront.decode(enc)}\n"
+end)