Toyama.rb #05 問題1

q1.rb

module Q1
  def self.count
    coins = [10, 50, 100, 500]

    result = []
    (2..15).each do |n|
      coins.repeated_combination(n).each do |cs|
        result << cs if cs.inject(:+) == 1000
      end
    end
    result.count
  end
end

puts "answer : #{Q1.count}" #=> answer : 20