//  File: bstree.h
//
//  A binary search tree template class

#ifndef _bstree_h
#define _bstree_h

#include "errors.h"


//  Template parameter TYPE must support:
//     constrructors, destructors, assignment, copying, comparison, <<
//

template <class TYPE>
class BSTree ;


template <class TYPE>
class BSTreeNode {
friend class BSTree<TYPE> ;

public:

   TYPE data ;                      // data in each tree node

   BSTree<TYPE> left ;              // left subtree
   BSTree<TYPE> right ;             // right subtree

   void *operator new(size_t) ;     // throws exceptions!
   void operator delete(void *) ;

protected:
   BSTreeNode() ;           // Constructors
   BSTreeNode(const TYPE&) ;
   BSTreeNode(const TYPE&, const BSTree<TYPE>&, const BSTree<TYPE>&) ;

   ~BSTreeNode() ;
} ;


template <class TYPE>
class BSTree {

public:
   BSTree() ;
   ~BSTree() ;

   void inorder() ;

   void insert(const TYPE&) ;

   BSTree *find(const TYPE&) ;      // Find node with given key
   void removeroot() ;              // Remove root of the subtree

   BSTree *min() ;                  // Find node with smallest key
   BSTree *max() ;                  // Find node with largest key

   bool empty() ;                   // 1 if empty, 0 otherwise

   BSTreeNode<TYPE> *root ;         // pointer to root BSTreeNode

   void *operator new(size_t) ;     // throws exceptions!
   void operator delete(void *) ;

protected:
   BSTreeNode<TYPE> *deletemin() ;  // remove and return node with min key
   BSTreeNode<TYPE> *deleteroot() ; // remove and return root node
} ;

#endif