From 40ee1eca5709784c3cbff94027e2058a7d72b6ce Mon Sep 17 00:00:00 2001
From: Alpha Chen <alpha.chen@gmail.com>
Date: Tue, 5 Dec 2017 21:09:15 -0800
Subject: [PATCH] [2017][ruby][6.x] speedrun

---
 2017/input/day_06.txt |  2 ++
 2017/ruby/day_06.rb   | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 2017/input/day_06.txt
 create mode 100644 2017/ruby/day_06.rb

diff --git a/2017/input/day_06.txt b/2017/input/day_06.txt
new file mode 100644
index 0000000..5839c56
--- /dev/null
+++ b/2017/input/day_06.txt
@@ -0,0 +1,2 @@
+4	10	4	1	8	4	9	14	5	1	14	15	0	15	3	5
+
diff --git a/2017/ruby/day_06.rb b/2017/ruby/day_06.rb
new file mode 100644
index 0000000..4f54a2f
--- /dev/null
+++ b/2017/ruby/day_06.rb
@@ -0,0 +1,27 @@
+banks = ARGF.read.strip.split("\t").map(&:to_i)
+
+history = { banks => true}
+count = 0
+seen = false
+loop do
+  v, i = banks.map.with_index {|v,i| [v,i] }.max_by(&:first)
+  banks[i] = 0
+  i += 1
+  while v > 0
+    banks[i % banks.size] += 1
+    v -= 1
+    i += 1
+  end
+  count += 1
+  if history.has_key?(banks)
+    if seen
+      puts count
+      exit
+    else
+      history.clear
+      seen = true
+      count = 0
+    end
+  end
+  history[banks] = true
+end