 same vertex.</li>
<li>The length of a path (<strong>path length</strong>) is the number of edges in that path.</li>
<li>Two vertices are said to be&nbsp;<strong>adjacent</strong> (or&nbsp;<strong>neighbors</strong>) if there is an edge between them.</li>
<li>A vertex&nbsp;is <strong>reachable</strong> from another vertex in a graph if a path exists to that vertex from the other.</li>
<li>A <strong>loop</strong> is an edge from some vertex to itself.</li>
<li>A <strong>complete graph</strong> is one in whic