From 40262304a10de936aff0b98c8526f7389a7f520f Mon Sep 17 00:00:00 2001
From: Eduardo Stalinho <eduardo.carvalho@olist.com>
Date: Wed, 20 Feb 2019 23:45:13 -0300
Subject: [PATCH] Adiciona romano em elixir (tem muito pra melhorar)

---
 romanos_20190213/roman.ex       | 38 ++++++++++++++++++++
 romanos_20190213/roman_test.exs | 61 +++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+)
 create mode 100644 romanos_20190213/roman.ex
 create mode 100644 romanos_20190213/roman_test.exs

diff --git a/romanos_20190213/roman.ex b/romanos_20190213/roman.ex
new file mode 100644
index 0000000..034776c
--- /dev/null
+++ b/romanos_20190213/roman.ex
@@ -0,0 +1,38 @@
+defmodule Roman do
+  def to_integer(I), do: 1
+  def to_integer(V), do: 5
+  def to_integer(X), do: 10
+  def to_integer(L), do: 50
+  def to_integer(C), do: 100
+  def to_integer(D), do: 500
+  def to_integer(M), do: 1000
+  def to_integer(x) do
+    list = to_list(x)
+    convert(list, 0)
+  end
+
+  defp to_list(x) do
+    [_, string] = String.split(Atom.to_string(x), ".")
+    String.codepoints(string)
+  end
+
+  defp get_value(numeral) do 
+    to_integer(String.to_atom("Elixir." <> numeral))
+  end
+
+
+  defp convert([first | [ second | tail] ], accumulator) do
+    cond do
+      get_value(first) >= get_value(second) -> convert([second | tail], accumulator) + get_value(first)
+      get_value(first) < get_value(second) ->  convert([second | tail], accumulator) - get_value(first)
+    end
+  end
+
+  defp convert([first | tail], accumulator) do
+    get_value(first) + convert(tail, accumulator) 
+  end
+
+  defp convert([], accumulator) do
+    accumulator
+  end
+end
diff --git a/romanos_20190213/roman_test.exs b/romanos_20190213/roman_test.exs
new file mode 100644
index 0000000..1d1e204
--- /dev/null
+++ b/romanos_20190213/roman_test.exs
@@ -0,0 +1,61 @@
+Code.require_file "roman.ex", __DIR__
+ExUnit.start()
+defmodule AssertionTest do
+  use ExUnit.Case, async: true
+
+  test "roman I returns 1" do
+    assert Roman.to_integer(I) == 1
+  end
+
+  test "roman V returns 5" do
+    assert Roman.to_integer(V) == 5
+  end
+
+  test "roman X returns 10" do
+    assert Roman.to_integer(X) == 10
+  end
+
+  test "roman L returns 50" do
+    assert Roman.to_integer(L) == 50
+  end
+
+  test "roman C returns 100" do
+    assert Roman.to_integer(C) == 100
+  end
+
+  test "roman D returns 500" do
+    assert Roman.to_integer(D) == 500
+  end
+
+  test "roman M returns 1000" do
+    assert Roman.to_integer(M) == 1000
+  end
+
+  test "roman II returns 2" do
+    assert Roman.to_integer(II) == 2
+  end
+
+  test "roman III returns 3" do
+    assert Roman.to_integer(III) == 3
+  end
+
+  test "roman VI returns 6" do
+    assert Roman.to_integer(VI) == 6
+  end
+
+  test "roman IV returns 4" do
+    assert Roman.to_integer(IV) == 4
+  end
+
+  test "roman XLII returns 4" do
+    assert Roman.to_integer(XLII) == 42
+  end
+
+  test "roman XXXIV returns 34" do
+    assert Roman.to_integer(XXXIV) == 34
+  end
+
+  test "roman MMXIX returns 2019" do
+    assert Roman.to_integer(MMXIX) == 2019
+  end
+end