# Supposedly Trivial math question.

Levi Pearson levipearson at gmail.com
Tue Oct 1 10:45:09 MDT 2013

```On Tue, Oct 1, 2013 at 10:33 AM, Adam Stevenson <adamstevenson at gmail.com> wrote:
> Yes, but the problem didn't say I had to read to the problem specifically.
> :)
>

What the problem *actually* says is that the denominational system is
strictly a place-value system of arbitrary base.  So all of the
denominations will be powers of the base.  The example is in base-10,
and specifically lists only powers of 10, not multiples of those
powers.  So, no \$20 bills, \$0.25 bills, etc.

The first step in these kind of interview problems is always
discussion to clarify that you understand the problem definition
correctly.  What is unclear, as far as I have read the definition, is
whether the amount to make change for is given to the algorithm in the
same base as the denominational system, or whether it's always given
in decimal and requires conversion to/from the base for input/output.
The latter just adds two base conversion steps to the general
algorithm, which is basically giving a place-value interpretation in
an arbitrary base to the result of the subtraction of price from
payment.
```