// File: avl.h

#ifndef _AVL_H_
#define _AVL_H_

#include <iostream>
#include <stdlib.h>

#define DTYPE int

class AVLNode ;

class AVL {

// friend class AVLNode ;
friend ostream& operator<< (ostream& os, const AVL& T) ;

public:

   AVL() ;
   AVL(const AVL& other) ;
   ~AVL() ;

   // inline member functions
   //
   bool empty() const { return nptr == NULL ; }  
   int height() const ;

   DTYPE* find(DTYPE x) ;
   void insert(DTYPE x) ;

   bool removeMax(DTYPE &answer) ;
   bool remove(DTYPE x, DTYPE &answer) ;

   void inorder() ;
   void inorder2() ;   // with parentheses
   void inorder3() ;   // with parentheses & height

   const AVL& operator=(const AVL& rhs) ;

   void dump() ;

private:
   AVLNode *nptr ;

   void updateHeight() ;
   void fixImbalance() ;
   AVLNode *removeMaxNode() ;   // should be private

} ;


ostream& operator<< (ostream& os, const AVL& T) ;


class AVLNode {

friend class AVL ;

public:
   AVLNode() ;
   AVLNode(DTYPE x) ;

   ~AVLNode() ;

   void dump() ;

private:
   DTYPE data ;
   int height ;
   AVL left, right ;
} ;



#endif