- implement the Expression Tree ADT (80 points)

- implement the following operations:

- constructor, copy constructor, assignment operator, destructor

- build, expression, evaluate

- clear

#include "ExpressionTree.h"

template

ExprTree::ExprTreeNode::ExprTreeNode ( char elem, ExprTreeNode *leftPtr, ExprTreeNode *rightPtr )

{

}

template

ExprTree::ExprTree ()

{

}

template

ExprTree::ExprTree(const ExprTree& source)

{

}

template

ExprTree& ExprTree::operator=(const ExprTree& source)

{

}

template

void ExprTree::copyHelper(ExprTreeNode *&p)

{}

template

ExprTree::~ExprTree ()

{

}

template

void ExprTree::build ()

{

}

#include ExpressionTree.h

template <>

void ExprTree::buildHelper(ExprTreeNode*& p)

{}

template <>

void ExprTree::buildHelper(ExprTreeNode*& p)

{}

template

void ExprTree::expression () const

{

}

template

void ExprTree::exprHelper(ExprTreeNode* p) const

{}

template

DataType ExprTree::evaluate() const throw (logic_error)

{

DataType temp;

return temp;

}

template <>

float ExprTree::evalHelper(ExprTreeNode* p) const

{

float temp;

return temp;

}

template <>

bool ExprTree::evalHelper(ExprTreeNode* p) const

{

bool temp;

return temp;

}

template

void ExprTree::clear ()

{

}

template

void ExprTree::clearHelper(ExprTreeNode *p)

{}

template

void ExprTree::commute()

{

}

template

void ExprTree::commuteHelper(ExprTreeNode* p)

{}

template

bool ExprTree::isEquivalent(const ExprTree& source) const

{

}

template

bool ExprTree::isEquivalentHelper(const ExprTreeNode* x,

const ExprTreeNode* y) const

{}

template

bool ExprTree::isEmpty() const

{

return false;

}

template

void ExprTree::showStructure() const

// Outputs an expression tree. The tree is output rotated counter-

// clockwise 90 degrees from its conventional orientation using a

// "reverse" inorder traversal. This operation is intended for testing

// and debugging purposes only.

{

// No isEmpty function in this class. Add a private one if you wish.

if (root == 0)

cout << "Empty tree" << endl;

else

{

cout << endl;

showHelper(root, 1);

cout << endl;

}

}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

template

void ExprTree::showHelper(ExprTreeNode *p, int level) const

// Recursive helper for the showStructure() function. Outputs the

// subtree whose root node is pointed to by p. Parameter level is the

// level of this node within the expression tree.

{

int j; // Loop counter

if (p != 0)

{

showHelper(p->right, level + 1); // Output right subtree

for (j = 0; j < level; j++) // Tab over to level

cout << "\t";

cout << " " << p->dataItem; // Output dataItem

if ((p->left != 0) && // Output "connector"

(p->right != 0))

cout << "<";

else if (p->right != 0)

cout << "/";

else if (p->left != 0)

cout << "\\";

cout << endl;

showHelper(p->left, level + 1); // Output left subtree

}

}

#Include "ExpressionTree.h"

///////////////////////////////////////////////

//--------------------------------------------------------------------

//

// Laboratory 8 ExpressionTree.h

//

// Class declarations for the linked implementation of the

// Expression Tree ADT -- including the recursive helpers for the

// public member functions

//

// Instructor copy with the recursive helper function declarations.

// The student version does not have those, but has a place to write

// the declarations in the private section.

//

//--------------------------------------------------------------------

#ifndef EXPRESSIONTREE_H

#define EXPRESSIONTREE_H

#include

#include

using namespace std;

template

class ExprTree {

public:

// Constructor

ExprTree ();

ExprTree(const ExprTree& source);

ExprTree& operator=(const ExprTree& source);

// Destructor

~ExprTree ();

// Expression tree manipulation operations

void build ();

void expression () const;

DataType evaluate() const throw (logic_error);

void clear (); // Clear tree

void commute();

bool isEquivalent(const ExprTree& source) const;

bool isEmpty() const;

// Output the tree structure -- used in testing/debugging

void showStructure () const;

private:

class ExprTreeNode {

public:

// Constructor

ExprTreeNode ( char elem,

ExprTreeNode *leftPtr, ExprTreeNode *rightPtr );

// Data members

char dataItem; // Expression tree data item

ExprTreeNode *left, // Pointer to the left child

*right; // Pointer to the right child

};

// Recursive helper functions for the public member functions -- insert

// prototypes of these functions here.

void buildHelper(ExprTreeNode*& p);

void exprHelper(ExprTreeNode* p) const;

DataType evalHelper(ExprTreeNode* p) const;

void clearHelper ( ExprTreeNode *p );

void showHelper ( ExprTreeNode *p, int level ) const;

void copyHelper ( ExprTreeNode *&p );

void commuteHelper(ExprTreeNode* p);

bool isEquivalentHelper(const ExprTreeNode* p,

const ExprTreeNode* q) const;

// Data member

ExprTreeNode *root; // Pointer to the root node

};

#endif // #ifndef EXPRESSIONTREE_H