From 753be41e956d82a687bd9a0b15ba1d10f28d8271 Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha.chen@gmail.com>
Date: Mon, 4 Dec 2017 07:31:53 -0800
Subject: [PATCH] [2017][ruby][4.0]

---
 2017/ruby/day_04.rb | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 2017/ruby/day_04.rb

diff --git a/2017/ruby/day_04.rb b/2017/ruby/day_04.rb
new file mode 100644
index 0000000..e41ec5e
--- /dev/null
+++ b/2017/ruby/day_04.rb
@@ -0,0 +1,24 @@
+class Passphrase
+  def initialize(raw)
+    @raw = raw
+  end
+
+  def valid?
+    words = @raw.split(/\s+/)
+    words.uniq.size == words.size
+  end
+end
+
+# require "minitest/autorun"
+if $0 == __FILE__
+  p ARGF.read.split("\n").map {|line| Passphrase.new(line) }.select(&:valid?).size
+end
+
+require "minitest"
+class TestPassphrase < Minitest::Test
+  def test_valid
+    assert Passphrase.new("aa bb cc dd ee").valid?
+    refute Passphrase.new("aa bb cc dd aa").valid?
+    assert Passphrase.new("aa bb cc dd aaa").valid?
+  end
+end