From: Ruby Quiz <james@...>
Date: 2008-01-26T00:50:38+09:00
Subject: [QUIZ] Making Change (#154)

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In "Practical Ruby Projects," the author includes a couple of chapters involving
coin simulations.  These simulators are used to explore the possibilities of
replacing a certain coin or adding a new coin.

One interesting subproblem of these simulations is that of making change.  For
example, if we need to give 39 cents change in the United States (where there
are 25, 10, 5, and 1 cent pieces), we can give:

	>> make_change(39)
	=> [25, 10, 1, 1, 1, 1]

What if the coins were 10, 7, and 1 cent pieces though and we wanted to make 14
cents change?  We would probably want to do:

	>> make_change(14, [10, 7, 1])
	=> [7, 7]

This week's Ruby Quiz is to complete a change making function with this
skeleton:

	def make_change(amount, coins = [25, 10, 5, 1])
	
	end

Your function should always return the optimal change with optimal being the
least amount of coins involved.  You can assume you have an infinite number of
coins to work with.