know that if</span></em><br /><em><span style="color: #236fa1;">         // root-&gt;right == nullptr, root-&gt;left can't be nullptr. If it were, then</span></em><br /><em><span style="color: #236fa1;">         // both children would be null, and we would have triggered the if condition</span></em><br /><em><span style="color: #236fa1;">         // above and never made it to this else-if condition.<br />         //</span></em><br /><em><span style="color: #236fa1;">         // In this case, we need to dele