// File: tree.C
//
// Implementation of Tree template class

#include <iostream.h>
#include <iomanip.h>
#include <stdlib.h>
#include "tree.h"


//======================================================================
// Implementation of TreeNode member functions

// homebrewed new operator. Might throw a MemoryError exception.
//
template <class TYPE>
void *TreeNode<TYPE>::operator new(size_t n) {

   void *ptr = malloc(n) ;
   if (ptr == NULL) {
      throw( MemoryError() ) ;
   }
   return ptr ;
}


// homebrewed delete operator.
//
template <class TYPE>
void TreeNode<TYPE>::operator delete(void *ptr) {

   if (ptr == NULL) return ;
   free(ptr) ;
}


//======================================================================
// Implementation of TreeNode member functions

// Constructors
//
template <class TYPE>
Tree<TYPE>::Tree() {
   root = NULL ;
}


template <class TYPE>
Tree<TYPE>::Tree(const TYPE& t) {

   root = new TreeNode<TYPE>(t) ;
}


template <class TYPE>
Tree<TYPE>::Tree(const TYPE& t, const Tree& left, const Tree& right) {

   root = new TreeNode<TYPE>(t) ;
   root->left = left ;
   root->right = right ;
}


// Destructor
//
template <class TYPE>
Tree<TYPE>::~Tree() {
   delete root ;
   root = NULL ;    // insurance, if this is part of a bigger tree
}


// Homebrewed new operator.  Might throw a MemoryError exception.
//
template <class TYPE>
void *Tree<TYPE>::operator new(size_t n) {

   void *ptr = malloc(n) ;
   if (ptr == NULL) {
      throw(MemoryError()) ;
   }
   return ptr ;
}


// Homebrewed delete operator.
//
template <class TYPE>
void Tree<TYPE>::operator delete(void *ptr) {

   if (ptr == NULL) return ;
   free(ptr) ;
}


// Perform an inorder tree traversal
//
template <class TYPE>
void Tree<TYPE>::inorder() {

    if (root == NULL) return ;

    root->left.inorder() ;
    cout << root->data << " " ;
    root->right.inorder() ;
}


// Perform an preorder tree traversal
//
template <class TYPE>
void Tree<TYPE>::preorder() {

    if (root == NULL) return ;

    cout << root->data << " " ;
    root->left.preorder() ;
    root->right.preorder() ;
}


// Perform a postorder tree traversal
//
template <class TYPE>
void Tree<TYPE>::postorder() {

    if (root == NULL) return ;

    root->left.postorder() ;
    root->right.postorder() ;
    cout << root->data << " " ;
}