place in a single room!),
it is a good way to explain the use of
<a href="http://en.wikipedia.org/wiki/Data_structure">data structures</a>.
</p>
<p>
We start by defining a
<a href="http://en.wikipedia.org/wiki/Struct_(C_programming_language)">struct</a>
to represent a location.
It contains two simple attributes to start with (more may follow later).
</p>
<ul>
<li><b>description:</b>
how the location is described in narrative text output by the program.
</li>
<li><b>tag:</b>
how the location is recognized by