// Small test program for the postorder traversal
#include "bintree2.h"

void addone(int& value)
{
    value++;
}

void main( )
{
    BinaryTreeNode<int>* root;
    BinaryTreeNode<int>* left;
    BinaryTreeNode<int>* right;
    BinaryTreeNode<int>* bottom;

    bottom = create_node(1);
    left = create_node(2, bottom);
    right = create_node(3);
    root = create_node(4, left, right);

    cout << "Original tree before adding one to each node: " << endl;
    print(root, 0);
    postorder(addone, root); // a parameter can be a function! p459
    cout << "New tree after adding one to each node: " << endl;
    print(root, 0);
}