sp;&nbsp;&nbsp;&nbsp;<strong>G</strong>&nbsp;&nbsp;&nbsp;&nbsp;<strong>F</strong></p>
<p>Notice that we start by visiting all vertices adjacent to <strong>C</strong> (namely, <strong>B</strong> and <strong>D</strong>). <span style="background-color: #ffff99;">Because we visited <strong>B</strong> before <strong>D</strong>, we must visit all neighbors of <strong>B</strong> (namely, <strong>A</strong>) before visiting all neighbors of <strong>D</strong>!</span> Then we visit all neighbors of <strong>D</strong