Make Change

def make_change(initial_cents=0)
    remaining_cents = initial_cents
    currency = {
        # values are in num cents
        "penny" => 1,
        "nickel" => 5,
        "dime" => 10,
        "quarter" => 25,
        "1 dollar" => 100,
        "5 dollar" => 500,
        "10 dollar" => 1000,
        "20 dollar" => 2000,
        "50 dollar" => 5000,
        "100 dollar" => 10000
    }
    change_made = []
    until remaining_cents == 0
        currency.reverse_each do |currency_name, currency_val|
            # go through currency_values starting at largest
            (remaining_cents / currency_val).times do
                change_made << currency_name
                remaining_cents -= currency_val
            end
            redo unless remaining_cents < currency_val
        end
    end
    result = change_made.group_by { |x| x }.values.map do |group|
        "#{group.length} #{group[0]}"
    end.join(", ")
    puts "making change from " + initial_cents.to_s + " cents: " + result.to_s
end

make_change(ARGV[0].to_i)

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