hight of binary tree

Height of a Binary Tree
For a tree with just one node, the root node, the height is defined to be 0, if there are 2
levels of nodes the height is 1 and so on. A null tree (no nodes except the null node)
is defined to have a height of –1.
The following height function in pseudocode is defined recursively as discussed in
class. It should be easily to add a C++ version to the program binTree1.cpp.
int height( BinaryTree Node t) {
if t is a null tree
return -1;
hl = height( left subtree of t);
hr = height( right subtree of t);
h = 1 + maximum of hl and hr;
return h;
{