The `Height` member function is implemented as
an `AVLTree` member variable accessor that simply returns the value
of the `height` member variable.
Clearly the running time of this function is constant.

The purpose of `AdjustHeight` is to recompute the height
of a node and to update the `height` member variable.
This routine must be called whenever the height of one of the subtrees
changes in order to ensure the `height` variable is always up to date.
The `AdjustHeight` routine determines the height of a node
by adding one to the height of the highest subtree.
Since the running time of the `Height` function is constant,
so too is the running time of `AdjustHeight`.

The `BalanceFactor` member function simply returns the
difference between the heights of the left and right subtrees
of a given AVL tree.
By Definition ,
the empty node is AVL balanced.
Therefore, the `BalanceFactor` routines zero for an empty tree.
Again, since the running time of the `Height` function is constant,
the running time of `BalanceFactor` is also constant.

Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.