Day 5 Ruby solutions

Author: creideiki

05-1.rb

@@ -0,0 +1,69 @@
+#!/usr/bin/env ruby
+
+class Rule
+  attr_reader :from, :to
+
+  def initialize(line)
+    @from, @to = line.split('|').map(&:to_i)
+  end
+
+  def inspect
+    to_s
+  end
+
+  def to_s
+    "<#{self.class}: #{@from} -> #{@to}>"
+  end
+end
+
+class Update
+  attr_reader :pages
+
+  def initialize(line)
+    @pages = line.split(',').map(&:to_i)
+  end
+
+  def satisfy?(rule)
+    first = @pages.find_index rule.from
+    last = @pages.find_index rule.to
+
+    return true if first.nil? or last.nil?
+
+    first < last
+  end
+
+  def score
+    @pages[@pages.size / 2]
+  end
+
+  def inspect
+    to_s
+  end
+
+  def to_s
+    "<#{self.class}: #{@pages}>"
+  end
+end
+
+class Puzzle
+  def initialize(input)
+    rules, updates = input.partition { |l| l.include? '|' }
+
+    @rules = rules.map { |r| Rule.new r }
+    @updates = updates.reject { |u| u == '' }.map { |u| Update.new u }
+  end
+
+  def score
+    @updates.map do |u|
+      if @rules.all? { |r| u.satisfy? r }
+        u.score
+      else
+        0
+      end
+    end.sum
+  end
+end
+
+input = File.read('05.input').lines.map(&:strip)
+puzzle = Puzzle.new(input)
+puts puzzle.score

05-2.rb

@@ -0,0 +1,83 @@
+#!/usr/bin/env ruby
+
+class Rule
+  attr_reader :from, :to
+
+  def initialize(line)
+    @from, @to = line.split('|').map(&:to_i)
+  end
+
+  def inspect
+    to_s
+  end
+
+  def to_s
+    "<#{self.class}: #{@from} -> #{@to}>"
+  end
+end
+
+class Update
+  attr_reader :pages
+
+  def initialize(line, rules)
+    @pages = line.split(',').map(&:to_i)
+    @rules = rules
+  end
+
+  def satisfy?(rule)
+    first = @pages.find_index rule.from
+    last = @pages.find_index rule.to
+
+    return true if first.nil? or last.nil?
+
+    first < last
+  end
+
+  def sort!
+    @pages.sort! do |a, b|
+      if @rules.any? { |r| r.from == a and r.to == b }
+        -1
+      elsif @rules.any? { |r| r.from == b and r.to == a }
+        1
+      else
+        0
+      end
+    end
+  end
+
+  def score
+    @pages[@pages.size / 2]
+  end
+
+  def inspect
+    to_s
+  end
+
+  def to_s
+    "<#{self.class}: #{@pages}>"
+  end
+end
+
+class Puzzle
+  def initialize(input)
+    rules, updates = input.partition { |l| l.include? '|' }
+
+    @rules = rules.map { |r| Rule.new r }
+    @updates = updates.reject { |u| u == '' }.map { |u| Update.new(u, @rules) }
+  end
+
+  def score
+    @updates.map do |u|
+      if not @rules.all? { |r| u.satisfy? r }
+        u.sort!
+        u.score
+      else
+        0
+      end
+    end.sum
+  end
+end
+
+input = File.read('05.input').lines.map(&:strip)
+puzzle = Puzzle.new(input)
+puts puzzle.score