/******************************************************

** Name: 

** Filename: TreeDrv.cpp

** Project #: Data Structures And Other Objects Using C++ 2nd Edition
              (Micheal Main & Walter Savich)
              <Expression Tree. Pg.513 Programming Project #1>

** Project Description: For this project, implement a 
   class for expression trees, including operations for 
   building expression trees.  Also include a function to 
   "evaluate" a non-empty expression tree.

** Output: - A simple tree diagram using the input string
           - The solution to the evaluated input expression
	     string.

** Input: An expression to be evaluated i.e. 14*(7+3) 

** Algorithm: 1. Instruct user to input an expression
              2. Check data input scanf()
	      3. Evaluate input expression
	      4. Print simple tree diagram using the input
		 string
	      5. Print out solution to the evaluated 
		 expression and tree.
              6. Ask user to try another expression or
		 end program

******************************************************/
// Include files
#include <iostream>  // used for cin, cout
#include <conio.h>
#include "Tree.h"
#include "Create.h"
using namespace std;

// Global Type Declarations

// Function Prototypes
bool toQuit();
void instruct (void);
void pause ();

//Global Variables - should not be used without good reason.

int main ()
{
	 // Declaration section
	    bool done = false;       // User Decides To Quit
	    CTree *head;
	    char expression[1000];
	    double res;

	 // Executable section
	 instruct ();

     while (!done) // While Not False Repeat
     {

	 printf("\nNOTE: This program only evaluates expressions containing + and *");
         printf("\nEnter Expression: "); // Printf used instead of cout
     
         // The string specifier %s scans the string and terminates when a space is found
	 scanf("%s",expression);

	 if(!HandleSum(expression,&head))
	 {
		printf("error parsing expression\n");
		return -1;
	 }

	 printf("\nExpression tree:\n\n");
	 res=head->Evaluate(0);
	 printf("\nFinal result: %.0f\n",res);

	 done = toQuit(); // Calls toQuit() Function To Continue Or End Prog.
     }

	 pause ();
	 return 0;
}

bool toQuit ()
{
    bool cont = true;     // While Will Repeat Unless cont = false
    bool toReturn = true; // Default Value Of True Unless Changed
    char response;        // Users Decision To Continue Or End Prog.
		
    while (cont)
    { 
      cout <<"\nWould you like to enter another expression? (Y/N) ";
      cin  >> response;
      cout <<"\n";

      if ((response != 'Y') && (response != 'y')
	 && (response != 'N') && (response != 'n'))
	  {                     // Error Because Did Not Use Y or N
	    cout <<"Invalid entry. Try again" << endl;
	  }                   

      if (response == 'Y' || response == 'y')
      { cont = false;       // User Continues
        toReturn = false;
      }            
      else if (response == 'N' || response == 'n')
      { cont = false;       // Stop Function
        toReturn = true;
            
      }

    }//End While
   
    return toReturn; // Returns True Or False To End

} // End Quit

void instruct (void)
{
	  // Declaration section
	  cout << "This program will take an input expression use it to create an "
	       << "expression tree\nand then evaluate the expression tree. It will "
	       << "also print out a simple diagram\nof an expression tree "
	       << "using the input and provide the solution to the evaluated expression."
               << " Input the expression in the following format: 14*(7+3) NO SPACES."
	       << "\n----------------------------------------------------"
	       << "---------------------------"
	       << endl;

	  // Executable section
}

void pause ()
{
    // Declaration section

    // Executable section
    cout << "\nPress any key to continue...";
    getch();
    cout << "\r";
    cout << "                            ";
    cout << "\r";
}


/*
Program Output

This program will take an input expression use it to create an expression tree
and then evaluate the expression tree. It will also print out a simple diagram
of an expression tree using the input and provide the solution to the evaluated
expression. Input the expression in the following format: 14*(7+3) NO SPACES.
-------------------------------------------------------------------------------

NOTE: This program only evaluates expressions containing + and *

Enter Expression: 14*(7+3)

Expression tree:

   14
*<
      7
   +<
      3

Final result: 140

Would you like to enter another expression? (Y/N)

*/