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

//             Jordi Binefa i Martínez

//                dubtes@excite.com

//           http://members.juara.com/asi

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



//Write the program SWITCH2.CPP to implement a four 

//functions single calculator. The program should 

//ask for the numbers and the function (+,-,* or /) 

//and should show the operation and the solution. 

//You may include the errors handling for the 

//"by zero division". 



//Escriu el programa SWITCH2.CPP que implementa una 

//calculadora simple de quatre funcions. El programa

//té que demanar l’operand i l’operador, i presentar 

//tant el teclejat com el resultat. Has d’incloure la 

//revissió d’errors a l’introduïr l’operand i l’intent 

//de dividir per zero. 

#include <iostream.h>



#define YES 1

#define NO 0

#define MAX_STRING 30



void askValues(double *b, double *c,

			char *bb, char *cc){



	cout << "Tell me the value of " << bb << " : ";

	cin >> *b;

	cout << "Tell me the value of " << cc << " : ";

	cin >> *c;

}



char operation(double a, double b, double *r){

        int possible;

	char resposta;



	do{

		possible = YES;

		cout << "\n Tell me the operation to do : ";

		cin >> resposta;

		switch(resposta){

			case '+' : *r = a + b;

					break;

			case '-' : *r = a - b;

					break;

			case '*' : *r = a * b;

					break;

			case '/' : if(b)

					*r = a / b;

				   else{

					   cout << "\nYou cannot divide by zero.\n";

					   possible = NO;

				   }

				    break;

			default : cout << "\nMay be +, -, * or /\n";

				      possible = NO;

		}

	}while(!possible);

	return resposta;

}



void main(){

	double x,y,res;

	char first_num[MAX_STRING] = "first number";

	char second_num [MAX_STRING] = "second number" ;



	askValues(&x,&y,first_num,second_num);

        cout << "\n\nThe solution is " << x << " "

		 << operation(x,y,&res) << " ";

	cout << y << " = " << res << "\n\n\n";

}