From: James Edward Gray II <james@...>
Date: 2007-07-16T01:44:59+09:00
Subject: Re: xkcd and ugly code

On Jul 15, 2007, at 3:08 AM, Sharon Phillips wrote:

> I read this xkcd strip the other day (http://www.xkcd.com/ 
> c287.html) and, of course, had to solve it.

Fun problem.  Thanks for sharing.

> There has to be a 'ruby way' to do this. Any suggestions?

Here's what I solved it with:

#!/usr/bin/env ruby -wKU

APPETIZERS  = { "Mixed Fruit"       => 215,
                 "French Fries"      => 275,
                 "Side Salad"        => 335,
                 "Hot Wings"         => 355,
                 "Mozzarella Sticks" => 420,
                 "Sampler Plate"     => 580 }
TOTAL_PRICE = 1505
MAX_COUNT   = TOTAL_PRICE / APPETIZERS.values.min

orders    =  Hash.new { |all, total| all[total] = Array.new }
orders[0] << Array.new
APPETIZERS.each do |name, price|
   orders.to_a.each do |total, items|
     1.upto(MAX_COUNT) do |count|
       cost = total + price * count
       break if cost > TOTAL_PRICE
       orders[cost] += items.map { |order| order + [name] * count }
     end
   end
end

puts "Orders costing $15.05:"
orders[1505].each do |order|
   puts( order.uniq.sort.map do |item|
     "  #{item} * #{order.select { |i| i == item }.size}"
   end )
   puts
end

__END__

James Edward Gray II