an arbitrary complete binary tree -- not a minheap.)</span></em><br /><em><span style="color: #236fa1;">   //</span></em><br /><em><span style="color: #236fa1;">   //</span></em><span style="color: #236fa1;">               9</span><br /><em><span style="color: #236fa1;">   //</span></em><span style="color: #236fa1;">             /   \</span><br /><em><span style="color: #236fa1;">   //</span></em><span style="color: #236fa1;">           3       7</span><br /><em><span style="color: #236fa1;">   //</span></e