#!/usr/bin/env ruby

require 'benchmark'

def ary(x,y,n)

  (n - 1).downto(1) do |i|

    y[i] = y[i] + x[i] 

  end

end

results = Benchmark.bmbm do |bm|

  raise "Expecting one arg - size of arrays" if ARGV.size == 0

  n = ARGV[0].to_i

  x = (0...n).to_a

  y = Array.new(n) { 0 }

  bm.report do 

    1000.times { ary(x, y, n) }

  end

end

puts "EXECUTION TIME: #{results[0].real * 1000.0}"