// merge t1, t2 and root (with rootItem)
#include "BinaryTree.h"
#include <iostream>
using namespace std;



// delete a tree rooted at "root"
void BinaryTree::deleteTree(BinaryNode *root)
{ // postorder traversal
if (root == NULL) return; // nothing to delete
if (root->left != NULL)
deleteTree(root->left);
if (root->right != NULL)
deleteTree(root->right);
delete root;
}