From 971f8c3c71662fa386d85c48d54b2f18d7fe40d3 Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha.chen@gmail.com>
Date: Mon, 3 Dec 2018 12:52:02 -0800
Subject: [PATCH] [2018][ruby][3.0]

---
 2018/ruby/day_03.rb | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 2018/ruby/day_03.rb

diff --git a/2018/ruby/day_03.rb b/2018/ruby/day_03.rb
new file mode 100644
index 0000000..af017ba
--- /dev/null
+++ b/2018/ruby/day_03.rb
@@ -0,0 +1,13 @@
+p ARGF.read.lines.each.with_object(Hash.new(0)) {|line, fabric|
+  line =~ /(\d+),(\d+): (\d+)x(\d+)$/
+  x = $1.to_i
+  y = $2.to_i
+  width = $3.to_i
+  height = $4.to_i
+
+  width.times {|dx|
+    height.times {|dy|
+      fabric[[y + dy, x + dx]] += 1
+    }
+  }
+}.count {|_,v| v > 1 }