// Name:  Alan Helms
// Class: CPT 232 C++ I
// Times: MWF 9:00 - 9:50
// Semester: Spring 3-14-2003
// Project Name: TenQs_vfx.cpp
// Program Purpose: This program is a 30 second math quiz. The program uses
//                  three functions which, one function returns one random number
//                  1 - 12, another returns one random character: +, -, *, /, %.
//						  The last function returns a result, which depends on the
//                  previous two functions. The timing feature uses the
//                  rand() function, also the header file <ctime>. These
//                  function generate either random integers or random characters.
//                  The values that are generated are used to ouput an
//                  mathematical expression which the user is to provide an answer.
//                  That answer is checked with the result of the third function.
//                  There is also a counter to keep record of the number question
//                  that were answered correctly.
//
//
// ****NOTE: THIS VERSION WAS CREATED WITH Microsoft Visual C++ EDITIOR****


#include <iostream>
using std::cin;
using std::cout;
using std::endl;

#include <iomanip>
using std::setprecision;
using std::setiosflags;
using std::setw;
using std::ios;

#include <cstdlib>
#include <ctime>


// The prototype for CalAnswer() function
int CalAnswer ( int, char, int);

// The prototype for RandNUM() function.
int RandNUM (int);

// The prototype for RandSIGN() function.
char RandOPS (int);

// The main program.
int main()
{

   int answer, nCorrect = 0;
   char yes_NO;

   cout << "Welcome to BRAIN STRAIN THE MATH GAME.\n\n"
	     << "BRAIN STRAIN is a 30 second arithmetic quiz.\n"
	     << "Your objective is to answer as many questions\n"
        << "correctly as you can within time allowed.\n"
	     << "**NOTE: \"/\" means integer division, \"%\" means\n"
		  << "modulus." << endl << endl;

   srand(time(0));

   cout << "To begin the quiz press \"y\". ";
   cin >> yes_NO;

   if (yes_NO == 'y'|| yes_NO == 'Y')
   {
	  int startTime = time(0);   // timer mechanism
	  for (int timer = 0; time(0) - startTime < 36; ++timer)
	  {

	  		int rNum1, rNum2;
	  		char rOpr1;

         // set the value randomly generated to a variable
         // then the variable is passed to the CalAnswer() function.
     		rNum1 = RandNUM(rand());   // call for the RandNUM() Function.
	  		rOpr1 = RandOPS(rand());   // call for the RandOPS() Function.
	  		rNum2 = RandNUM(rand());   // call for the RandNUM() Function.
	  		cout << rNum1 << " " << rOpr1 << " " << rNum2 << " = ";
	  		cin >> answer;

	  		cout << endl;

        	// the variables are passed into the CalAnswer() function
         // and checked against the user supplied answer.
	  		if ( CalAnswer(rNum1, rOpr1, rNum2) == answer)
	  		{
	  			cout << "Correct!!" <<endl;
	  			++nCorrect;
	  		}
	  		else
	  			cout << "Wrong!!!" << endl;

	  		cout << endl;

	  } // end for timer

	  // output the number of question that the user got right.
	  cout<< "You got " << nCorrect << " correct. Thanks for playing!" << endl;

	} // end if yes_no
   else
	   cout << "Program Ended." << endl;

   return 0;


} // end main program

//
// Implementation for the fucntion RandNUM().
// This function calculates a random number from within the range fo 1 to 12.
int RandNUM (int num1)
{
	int num2;
	num2 = 1 + num1 % 12; // stepping value + rand() % total nums;
   return num2;
} // end RandNUM().

// Implemetation for the RandOPS() function.
// This Function generates an operator of one of the following:
// *,/,%,+,-.
char RandOPS(int ops)
{
	switch ( ops % 5 )
   {
   		case 0:
            ops = '+';
            break;
        case 1:
            ops = '-';
            break;
		case 2:
            ops = '*';
            break;
		case 3:
            ops = '/';
            break;
		case 4:
           	ops = '%';
            break;
   } // end switch

   return ops;

} // end RandSIGN().

// Imepelmentation for the CalAnswer() function.
// This Function will calculate the answer to the all of the question
// generated.
int CalAnswer (int x, char y, int z)
{
	int nResult;
	switch (y){
		case '+':
			nResult = x + z;
			break;
		case '-':
			nResult = x - z;
			break;
		case '*':
			nResult = x * z;
			break;
		case '/':
			nResult = x / z;
			break;
		case '%':
			nResult = x % z;
			break;
	} // end switch

	return nResult;
}