/***************************************************************************
Name of program: Tom's Calculator v1.0

Name of file: calc.cpp

What the program does: executes 8 different mathematical functions,
4 simple, 4 advanced

Creator name: Tom Kralidis

Date: October 22, 1998

Miscellaneous: Program begins with a start menu (9 options).
After a selection is made, the user is prompted to enter
a number (or numbers) to perform the chosen function.
Following execution, the screen is cleared and the
user is prompted back to the start menu if he/she chooses.

The quit option automatically terminates the program, with
no return to the main menu.
****************************************************************************/

#include <iostream.h>	
#include <conio.h>
#include <math.h>

/***************************************************************************
These are the function prototypes, always placed before main. They are user
defined. Can be thought of as supplements to the libraries.
***************************************************************************/

addition();
subtraction();
multiplication();
division();
square();
squareroot();
inverse();
log();
quit();

int main()
{
	int choice = 0;
	int pick;
	// This initializes choice to 0
	do
	{
			 

			cout <<"Welcome to Tom's Calculator v1.0\n\n";

			cout <<"Choose your function from the following list\n\n";

			cout << "\t1.   addition \n";

			cout << "\t2.   subtraction \n";

			cout << "\t3.   multiplication \n";

			cout << "\t4.   division \n";

			cout << "\t5.   square \n";

			cout << "\t6.   squareroot \n";

			cout << "\t7.   natural log \n";

			cout << "\t8.   inverse \n";

			cout << "\t9.   quit \n";

			cout << "\nWhat is your choice?\n\n";

			cin >> choice;

			 

			while ( choice < 1 || choice > 9 )
			{
				 cout << "\nIllegal choice, enter a number from 1 to 9\n\n";

				 cin >> choice;
			}

		/**********************************************************************
	  Switch from variable of choices, the cases call the
	  selected functions, and break to them
	  ***********************************************************************/

			switch (choice)
			{
				case (1):  addition();
					break;
				case (2):  subtraction();
					break;
				case (3):  multiplication();
					break;
				case (4):  division();
					break;
				case (5):  square();
					break;
				case (6):  squareroot();
					break;
				case (7):  log();
					break;
				case (8):  inverse();
					break;
				case (9):  quit();
					break;
			}

			if ( choice != 9 )
			{
				cout << "\n\nBack to the Main Menu? \n\t[1] Yes\n\t[2] No\n\t";

				cin >> pick;
			
				if ( pick == 2 )
				{
					quit();

					return 0;
				}

			}
		}
	while ( choice != 9 );

	return 0;
}

  /*************************************************************************
  The functions below are the eight mathematical functions
  and the quit function.
  **************************************************************************/

addition()
{
	float num1, num2, sum;

	cout << "\nWelcome to Tom's Addition!\n\n";

	cout << "Enter first integer:\n\n";

	cin >> num1;

	cout << "\nEnter second integer:\n\n";

	cin >> num2;

	sum = num1 + num2;

	cout << "\nThe sum is " << sum << "\n" << endl;

	return 0;
}

subtraction()
{
	float num1, num2, difference;

	cout << "\nWelcome to Tom's Subtraction!\n\n";

	cout << "Enter first integer:\n\n";

	cin >> num1;

	cout << "\nEnter second integer:\n\n";

	cin >> num2;

	difference = num1 - num2;

	cout << "\nThe difference is " << difference << "\n" << endl;

	return 0;
}

multiplication()
{
	float num1, num2, product;

	cout << "\nWelcome to Tom's Multiplication!\n\n";

	cout << "Enter first integer:\n\n";

	cin >> num1;

	cout << "\nEnter second integer:\n\n";

	cin >> num2;

	product = num1 * num2;

	cout << "\nThe product is " << product << "\n" << endl;

	return 0;
}

division()
{
	float num1, num2, quotient;

	cout << "\nWelcome to Tom's Division!\n\n";

	cout << "Enter first integer:\n\n";

	cin >> num1;

	cout << "\nEnter second integer:\n\n";

	cin >> num2;

	while ( num2 == 0)
	{
		 cout << "\nCannot divide by zero, choose another number:\n\n";

		 cin >> num2;
	}

	quotient = num1 / num2;

	cout << "\nThe quotient is " << quotient << "\n" << endl;

	return 0;
}

square()
{
	float num1, square;

	cout << "\nWelcome to Tom's Squares!\n\n";

	cout << "Enter an integer:\n\n";

	cin >> num1;

	square = num1 * num1;

	cout << "\nThe square of " << num1 << " is " << square << "\n" << endl;

	return 0;
}

	/************************************************************************
	This begins the functions that work off the <math.h> file,
	declared at the start of this program.  The assignment of sqrt(num1)
	runs off the this header file
	*************************************************************************/

squareroot()
{
	double num1, sqroot;

	cout << "\nWelcome to Tom's Square Root!\n\n";

	cout << "Enter an integer\n\n";

	cin >> num1;

	sqroot = sqrt(num1);

	cout << "\nThe square root of " << num1 << " is " << sqroot << "\n" << endl;

	return 0;
}

log()
{
	double num1, logg;

	cout << "\nWelcome to Tom's Log of a Number!\n\n";

	cout << "Enter an integer\n\n";

	cin >> num1;

	while ( num1 == 0)
	{
		 cout << "\nEnter an integer other than zero:\n\n";

		 cin >> num1;
	}

	logg = log(num1);

	cout << "The answer is " << logg << endl;

	return 0;
}

inverse()
{
	double num1, inverse;

	cout << "\nWelcome to Tom's Inverse of a Number!\n\n";

	cout << "Enter an integer\n\n";

	cin >> num1;

	while ( num1 == 0)
	{
		 cout << "\nEnter an integer other than zero:\n\n";

		 cin >> num1;
	}

	inverse = 1.0/num1;

	cout << "The answer is " << inverse << endl;

	return 0;
}

quit()
{
	 

	cout << "\nThank you for trying Tom's Calculator v1.0!!\n\n";

	cout << "Comments, bugs and general info on this software can be sent to:\n\n";

	cout << "\tTom Kralidis\n\t(613) 233-4921\n\ttommy@storm.ca\n\n";

	return 0;
}