#ifndef EXPRESSIONTREE$\_$H

#define EXPRESSIONTREE$\_$H

#include

#include

using namespace std;

#pragma warning$($ disable : $4290)$

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;

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

void showStructure $()$ const;

bool isEmpty$()$ 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 showHelper $($ ExprTreeNode $*$p$,$ int level $)$ const;

$//$ Data member

ExprTreeNode $*$root; $//$ Pointer to the root node

$\}$;

#endif $//$ #ifndef EXPRESSIONTREE$\_$H