Day twenty-five Part one

25/main.rb

@@ -0,0 +1,69 @@
+#!/usr/bin/env ruby
+
+class Component < Array
+  def self.from_line(line)
+    new(line.map(&:chars)[1..-2].transpose.map { _1.count("#") })
+  end
+end
+
+class Lock < Component
+  def accepts?(key) = zip(key).all? { _1.sum <= 5 }
+end
+
+Key = Class.new(Component)
+
+def create(line)
+  (line.first == "#####" ? Lock : Key).from_line(line)
+end
+
+input = (ARGV.first.nil? ? DATA : ARGF)
+  .readlines(chomp: true)
+  .slice_when { |a, b| b.empty? }
+  .map { _1.reject { |a| a.empty? } }
+  .map(&method(:create))
+
+locks, keys = input.partition { _1.is_a?(Lock) }
+
+p locks.sum { |lock| keys.count { lock.accepts?(_1) } }
+
+
+__END__
+#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####