make_change - dynamic programming

gistfile1.txt

require 'benchmark'

def make_change(change, *coins)
  coins.empty? ? coins = [200, 100, 50, 20, 10, 5, 2, 1] : coins = coins.flatten
  denom = []
  c = Array.new(change) {|index| index = Float::INFINITY}.unshift(0)
  (1..change).each do |j|
    coins.each do |coin|
      if j >= coin && 1+c[j-coin] < c[j]
        c[j] = 1+c[j-coin]
        denom[j] = coin
      end
    end
  end
  recursive_print = lambda { |denom, n|
    if n > 0
      print "[" + denom[n].to_s + "]"
      recursive_print.call(denom, n - denom[n])
    end
  }
  recursive_print.call(denom, change)
end

Benchmark.bmbm do |b|
  b.report("1984") {make_change(1984)}
end