/*  BSTree2.h
 *
 *  Interface for Binary Search Tree class WITH
 *  deletion.
 */

#ifndef _BSTREE_H_
#define _BSTREE_H_

typedef	 int    DATA_TYPE;  // Type of node's data

class BinarySearchTree {
  private:
    typedef struct  BSTreeNode {
       DATA_TYPE     data;
       BSTreeNode   *leftPtr;
       BSTreeNode   *rightPtr;
    } *TreePtr;
    
    TreePtr rootPtr;   //  root of the BST
    
    void     InitBSTree()
                 { rootPtr = NULL; }
    void     DeleteBST( TreePtr& treePtr );
    
    void     DeleteNode(
                     TreePtr& treePtr, DATA_TYPE theItem );
    void     DeleteNodeItem( TreePtr& treePtr );
    void     ProcessLeftMost(
                     TreePtr& treePtr, DATA_TYPE& theItem );
                     
    bool     IsLeaf( TreePtr treePtr );
        
    TreePtr  SearchNodeInBST( TreePtr treePtr,
                              DATA_TYPE searchKey );
    
    void     PrintBST_InOrder(   TreePtr treePtr );
    void     PrintBST_PreOrder(  TreePtr treePtr );
    void     PrintBST_PostOrder( TreePtr treePtr );
    
    void     PrintBST_BackwardPostOrder( TreePtr treePtr, int depth );
 
  public:
    BinarySearchTree() 
                 { InitBSTree(); }
    ~BinarySearchTree();
    
    bool     IsEmpty()
                 { return (rootPtr == NULL); }
    
    void     AddNode( DATA_TYPE newData );
    void     SearchNode( DATA_TYPE searchKey );
    void     DeleteNode( DATA_TYPE val );
    
    void     PrintTree();
    
    void     PrintInOrder();
    void     PrintPreOrder();
    void     PrintPostOrder();
    
    void     PrintBackwardPostOrder();
};

#endif