From 39f73f693594b480c66d1c71e610dee851ccc581 Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha.chen@gmail.com>
Date: Tue, 13 Dec 2016 08:26:31 -0800
Subject: [PATCH] [2016][ruby][12.0]

---
 2016/ruby/day_12.rb | 51 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 2016/ruby/day_12.rb

diff --git a/2016/ruby/day_12.rb b/2016/ruby/day_12.rb
new file mode 100644
index 0000000..85b45c7
--- /dev/null
+++ b/2016/ruby/day_12.rb
@@ -0,0 +1,51 @@
+registers = Hash[(?a..?d).map {|c| [c, 0] }]
+pc = 0
+data = DATA.each_line.to_a
+
+while pc < data.size
+  line = data[pc]
+  case line
+  when /cpy ([a-d]|\d+) ([a-d])/
+    value = registers.fetch($1) { $1.to_i }
+    registers[$2] = value
+    pc += 1
+  when /inc ([a-d])/
+    registers[$1] += 1
+    pc += 1
+  when /dec ([a-d])/
+    registers[$1] -= 1
+    pc += 1
+  when /jnz ([a-d]|\d+) (-?\d+)/
+    value = registers.fetch($1) { $1.to_i }
+    pc += value.zero? ? 1 : $2.to_i
+  else
+    raise "invalid line: #{line}"
+  end
+end
+
+p registers
+
+__END__
+cpy 1 a
+cpy 1 b
+cpy 26 d
+jnz c 2
+jnz 1 5
+cpy 7 c
+inc d
+dec c
+jnz c -2
+cpy a c
+inc a
+dec b
+jnz b -2
+cpy c b
+dec d
+jnz d -6
+cpy 16 c
+cpy 17 d
+inc a
+dec d
+jnz d -2
+dec c
+jnz c -5