From 53f60cb5651969e45acada9e3d6695ab89faa0a5 Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha.chen@gmail.com>
Date: Thu, 1 Dec 2016 21:26:26 -0800
Subject: [PATCH] [2016][ruby][2.0]

---
 2016/ruby/day_02.rb | 81 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 2016/ruby/day_02.rb

diff --git a/2016/ruby/day_02.rb b/2016/ruby/day_02.rb
new file mode 100644
index 0000000..7650428
--- /dev/null
+++ b/2016/ruby/day_02.rb
@@ -0,0 +1,81 @@
+class Keypad
+  MAP = (1..9).each_slice(3).to_a
+
+  attr_reader :x, :y
+
+  def initialize
+    @x, @y = 1, 1
+  end
+
+  def button
+    MAP[y][x]
+  end
+
+  def <<(dir)
+    delta = case dir
+            when ?U
+              [0, 1]
+            when ?D
+              [0, -1]
+            when ?L
+              [-1, 0]
+            when ?R
+              [1, 0]
+            else
+              raise "unexpected direction: '#{dir}'"
+            end
+    @x += delta[0]
+    @y -= delta[1]
+
+    @x = [[2, x].min, 0].max
+    @y = [[2, y].min, 0].max
+  end
+end
+
+if __FILE__ == $0
+  keypad = Keypad.new
+  code = DATA.read.lines.map {|line|
+    line.strip.chars.each do |char|
+      keypad << char
+    end
+    keypad.button
+  }
+  puts code.join
+end
+
+require 'minitest'
+# require 'minitest/autorun'
+
+class TestDay2 < Minitest::Test
+  def test_day2
+    keypad = Keypad.new
+    assert_equal 5, keypad.button
+
+    'ULL'.chars.each do |char|
+      keypad << char
+    end
+    assert_equal 1, keypad.button
+
+    'RRDDD'.chars.each do |char|
+      keypad << char
+    end
+    assert_equal 9, keypad.button
+
+    'LURDL'.chars.each do |char|
+      keypad << char
+    end
+    assert_equal 8, keypad.button
+
+    'UUUUD'.chars.each do |char|
+      keypad << char
+    end
+    assert_equal 5, keypad.button
+  end
+end
+
+__END__
+RDRRDLRRUDRUUUULDDRDUULLDUULDURDDUDRULDLUDDRLRDUDDURRRRURDURLLRDRUUULDLLLURDRLLULLUULULLLDLLLRRURRLRDUULRURRUDRRDRLURLRURLLULRUURRUURDDLDRDLDLLUDUULLLUUUUDULLDRRUURLDURDDDDDRLLRRURDLUDRRUUDLRRLLRDURDUDDDLRDDRDLRULLUULRULRLLULDDRURUUDLDDULDRLLURDDUDDUDRDUDLDRRRDURRLDRDRLDLLDUDDDULULRRULRLLURDRRDDUUUUUULRUDLRRDURDLRDLUDLDURUDDUUURUDLUUULDLRDURDLDUUDLDDDURUUDUUDRLRDULLDUULUDRUDRLRRRDLLDRUDULRRUDDURLDRURRLLRRRDRLLDLULULRRUURRURLLUDRRLRULURLDDDDDURUDRRRRULLUUDLDDLUUL
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
+URLURDDRLLURRRLDLDLUDUURDRUDLLLRRDLUUULRRLURRRLUDUDLRLDDRUDLRRRULUDUDLLLULULLLRUDULDDDLLLRRRLRURDULUDDDULDLULURRRDLURDLRLLDUDRUDURDRRURULDRDUDLLRDDDUDDURLUULLULRDRRLDDLDURLRRRLDRDLDULRULRRRLRLLDULRDLURLRUUDURRUUDLLUDRUDLRLDUUDLURRRDDUUDUDRLDLDDRURDDLLDDRDLRLRDLLLUDLUUDRLRLRDDRDLRDLLUULLLLUULLDLLDLRDLRLRRLUUDLLRLRUDRURULRLRLULUDRLLUDDUDDULRLDDRUUUURULDRRULLLDUURULUDRLLURLRRLDLRRLDDRRRDUDDUDLDDLULUDDUURDLLLRLDLRDRUUUUUDDDLDRDDRRRLRURRRRDURDRURUDLURRURDRLRUUDDLDRRULLDURDRLRRDURURUULRDUDLDRDDLULULRDRRUDDRLLRLULRLLUUDRDUUDDUDLRUUDLLUULLRUULUDDLURRRLLDRLRRLLRULLDUULURLLLLUUULDR
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
+LURLUURLURDUUDRUDLDLLURRRDLDRRRULDDRRDRDUUDRUDURDDDURLUDDLULUULRRLLRULUDRDDRRRLDURDUDDURDDDLRLDDLULLDRDDLUUDUURRRLULRUURRRRLLULDUDRDUURRRURRDRDUDUDLUDULLDLDDRLUDRURDULURLURRLLURLLLRLUURLRUDLUDDRLURRUULULRLURRURUDURDLDLDDUDDRDLLRLLRRULDDRUDURUDDDUDLLRDLRUDULLLRRRUURUDUUULLRDUDRURUDULLDLLUUUDRULRLLRRDDDDUDULDRDRLLDDLLDDDURRUDURLDLRDRUURDDURLRDRURLRRLLRLULDRRLRUDURDUURRLUUULUDDDLRLULRDRLLURRRDLURDUUDRRRLUURRLLUDLUDLUULLRRDLLRDDRURRUURLDDLRLRLRUDLDLRLRDRRDLLLRDLRDUDLLDDDRD