Data commit

Task/Roman-numerals-Encode/Elixir/roman-numerals-encode-1.elixir

@@ -0,0 +1,17 @@
+defmodule Roman_numeral do
+  def encode(0), do: ''
+  def encode(x) when x >= 1000, do: [?M | encode(x - 1000)]
+  def encode(x) when x >= 100,  do: digit(div(x,100), ?C, ?D, ?M) ++ encode(rem(x,100))
+  def encode(x) when x >= 10,   do: digit(div(x,10), ?X, ?L, ?C) ++ encode(rem(x,10))
+  def encode(x) when x >= 1,    do: digit(x, ?I, ?V, ?X)
+
+  defp digit(1, x, _, _), do: [x]
+  defp digit(2, x, _, _), do: [x, x]
+  defp digit(3, x, _, _), do: [x, x, x]
+  defp digit(4, x, y, _), do: [x, y]
+  defp digit(5, _, y, _), do: [y]
+  defp digit(6, x, y, _), do: [y, x]
+  defp digit(7, x, y, _), do: [y, x, x]
+  defp digit(8, x, y, _), do: [y, x, x, x]
+  defp digit(9, x, _, z), do: [x, z]
+end

Task/Roman-numerals-Encode/Elixir/roman-numerals-encode-2.elixir

@@ -0,0 +1,10 @@
+defmodule Roman_numeral do
+  @symbols [ {1000, 'M'}, {900, 'CM'}, {500, 'D'}, {400, 'CD'}, {100, 'C'}, {90, 'XC'},
+             {50, 'L'}, {40, 'XL'}, {10, 'X'}, {9, 'IX'}, {5, 'V'}, {4, 'IV'}, {1, 'I'} ]
+  def encode(num) do
+    {roman,_} = Enum.reduce(@symbols, {[], num}, fn {divisor, letter}, {memo, n} ->
+                  {memo ++ List.duplicate(letter, div(n, divisor)), rem(n, divisor)}
+                end)
+    Enum.join(roman)
+  end
+end

Task/Roman-numerals-Encode/Elixir/roman-numerals-encode-3.elixir

@@ -0,0 +1,3 @@
+Enum.each([1990, 2008, 1666], fn n ->
+  IO.puts "#{n}: #{Roman_numeral.encode(n)}"
+end)