BSTree::BSTree() 
{
  ptr = NULL; // indicates an empty list
}
BSTree::~BSTree()
{
  // Add a destructor to delete the list on exit
  // otherwise you will end up with a memory leak
}
void BSTree::addNode(int data)
{
  // create a new record (struct)
  // use a *curr for traversing
  if(curr == NULL)
  {
    // List is empty so add the first record (struct). 
  }
  else
  {
    // There are records in list, so traverse according to rules until curr=NULL
    // and insert new record. - exit the loop using a break. 
    while (curr != NULL)
    {
    }
  }
}

#include <iostream>
using namespace std;
 
///////////////////////////////////////////////
// tnode structure
typedef struct tnode
{
	int data;
	struct tnode *leftChild;
	struct tnode *rightChild;
}TNODE;
 
///////////////////////////////////////////////
//Binary search tree class
 
class BSTree
{
public:
	BSTree(void);
 
	void addNode(int data);
	TNODE *findNode(TNODE *ptr, int data);
	void printTree(TNODE *ptr, int level);
	TNODE *getRoot(void);
private:
	TNODE* ptr;	
};
 
///////////////////////////////////////////////
//main
 
int main()
{
	BSTree mytree;
	int level = 1;
 
	TNODE* tree;
	int i, numbers[] = {9, 7, 15, 5, 8, 14, 20, 4};
 
	for(i = 0; i < 8; i++)
		mytree.addNode(numbers[i]);
	mytree.printTree(mytree.getRoot(), level);
	return 0;
}
 
////////////////////////////////////////////////
//methods
 
BSTree::BSTree() 
{//constructor
	ptr = NULL; // indicates an empty list
} 
 
void BSTree::addNode(int data)
{//adds root to the tree. 
	if(ptr == NULL)
	{ 
		TNODE* newnode1 = new TNODE;
		newnode1->data = data;
		newnode1->leftChild = NULL;
		newnode1->rightChild = NULL;
		ptr = newnode1;
	}
	else
		findNode(ptr, data);
}
 
TNODE *BSTree::findNode(TNODE *ptr, int data)
{//finds where to add the node. Traverse through tree then add the node.
 	if(ptr == NULL)
	{ 
		TNODE* newnode1 = new TNODE;
		newnode1->data = data;
		newnode1->leftChild = NULL;
		newnode1->rightChild = NULL;
		ptr = newnode1;
		return ptr;
	}
	else if(data < ptr->data)
	{
		ptr->leftChild = findNode(ptr->leftChild, data);
	}
	else
		ptr->rightChild = findNode(ptr->rightChild, data);
	return ptr;
}
 
void BSTree::printTree(TNODE *ptr, int level)
{//prints out the tree on its side
	if(ptr != NULL)
	{
		printTree(ptr->rightChild, level + 1);
		for(int i = 0; i < 3 * level; i++)
			cout << " ";
		cout << ptr -> data << endl;
		printTree(ptr->leftChild, level + 1);
	}
}
 
TNODE *BSTree::getRoot(void)
{//returns the root pointer
	return (ptr);
}