de </strong>*root)<br />{<br /><span style="color: #236fa1;"><em>   // Recall that the height of a tree with a single node is zero (0).<br />   // If this node has no children, then we can simply return its height.</em></span><br />   <strong>if</strong> (root-&gt;left == <strong>nullptr</strong> &amp;&amp; root-&gt;right == <strong>nullptr</strong>)<br />   {<br /> &nbsp; &nbsp; &nbsp;<strong>return</strong> 0;<br />   }<br /><br />   <strong>return</strong> 1 + max(height(root-&gt;left), height(root-&gt;r