 For example, in the following diagram, the height of the root's left subtree<br />// (the subtree rooted at 3) is 2. The height of the root's right subtree (the<br />// subtree rooted at 7) is 1. The max of those two values (2 vs. 1) is 2. We add<br />// 1 to that to get the overall height of the tree. (Adding 1 accounts for the<br />// extra level that is added when we unite the left and right subtree beneath the<br />// root node.)<br />//<br />//</em>                           9                        |