Largest Product of Five (Euler 8)

euler-8.rb

def largest_product(digits)
  product_of_five(digits).max
end
def product_of_five(digits)
  digit_array = digits.to_s.split("")
  digit_array[0..-5].map.with_index do |digit, i|
    digit.to_i * digit_array[i+1].to_i * digit_array[i+2].to_i * digit_array[i+3].to_i * digit_array[i+4].to_i
  end
end