#include <iostream>
using namespace std;
 
int main(void)
{
	system("TITLE calculator");
	system("COLOR 9");
	char cChar;
	double dfirstnumber;
	double dsecondnumber;
	char cDoagain;
 
do
{
	 system("CLS");
	 cout << "please enter the first number that you would like to use" << endl;
	 cin >> dfirstnumber;
 
	 cout << "please enter the operation that you would like to complete" << " (+,-,* or /) " << endl;
	 cin >> cChar;
 
	 cout << "please enter the second number you would like to use" << endl;
	 cin >> dsecondnumber;
 
	 switch (cChar)
	 {
		case '+':
			cout << " the answer is: " << dfirstnumber << " + " << dsecondnumber << " = " << 
	     	   (dfirstnumber + dsecondnumber) << endl;
			break;
 
		case '-':
			 cout << "the answer is: " << dfirstnumber << " - " << dsecondnumber << " = " << 
			    (dfirstnumber - dsecondnumber) << endl;
	 		break;
 
	                case '*':
			 cout << "the answer is: " << dfirstnumber << " * " << dsecondnumber << " = " << 
			    (dfirstnumber * dsecondnumber) << endl;
			break;
		case 'X':
			 cout << "the answer is: " << dfirstnumber << " X " << dsecondnumber << " = " << 
			    (dfirstnumber * dsecondnumber) << endl;
			break;
	                case 'x':
			 cout << "the answer is: " << dfirstnumber << " x " << dsecondnumber << " = " << 
			    (dfirstnumber * dsecondnumber) << endl;
			break;
 
		case '/':
		 if (dsecondnumber == 0) {
			 cout << " that is invalid " << endl;
		 }else{
		     cout << "the answer is: " << dfirstnumber << "/" << dsecondnumber << "=" << 
		     (dfirstnumber / dsecondnumber) << endl;
		 }	
 
		 break;	
	 default 
		 cout << "that is an invalid operation" << endl;
	     break;
	 }
	 cout << "would you like to start again? (y or n)" << endl;
                   cin >> cDoagain;
 
	}while (cDoagain == 'y' || cDoagain == 'Y');
 
	system("PAUSE");
 
    return 0;
}