credit_check.rb

credit_check

account_number = "5541808923795240"

cc_number = account_number.chars.map do |num|
  num.to_i
end

doubled_digits = cc_number.map.with_index do |num, index|
  if index.even?
    num * 2
  else
    num
  end
end

sum_over_10 = doubled_digits.map do |num|
  if num > 9
    num -= 9
  else
    num
  end
end

total = sum_over_10.reduce(:+) % 10
  if total == 0
    puts "Card is valid"
  else
    puts "Card is invalid"
end