#include <iostream>
using namespace std;

int main(void)
{
    
    system("TITLE Calculator");
    system("COLOR 2");
    char cChar;
    double dfirstnumber;
    double dsecondnumber;
    char cDoagain;
    
    do
    {
         system("CLS");
         
         cout << "Please enter the first number you would like to use" << endl;
         cin >> dfirstnumber;
         
         cout << "Please enter the operation that you would like to do" << endl;
         cin >> cChar;
         
         cout << "Please enter the second number" << 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 an invalid operation." << endl;
                     }
                     
                     else {
                          
                     cout << "The answer is: " << dfirstnumber << " / " << 
                          dsecondnumber << " = " << (dfirstnumber / dsecondnumber)
                          << endl;
                     }
                     break;
                default:
                        cout << "Invalid selection" << endl;
                        break;
                }
                
                cout << "Do again? (y or n)" << endl;
                cin >> cDoagain;
         }while (cDoagain == 'Y' || cDoagain == 'y');
    system("PAUSE");
    return 0;
}