C++'da Hesap Makinesine Mod İşlemi Ekleme

# include <stdio.h>


int main() {

    char operator;
    double firstNumber,secondNumber;

    printf("Enter the operator you want to do process(+, -, *, /): ");
    scanf("%c", &operator);

    printf("Enter the first number you want to do process: ");
    scanf("%lf",&firstNumber);
   
    printf("Enter the second number you want to do process: ");
    scanf("%lf",&secondNumber);

    switch(operator)
    {
        case '+':
            printf("%.2lf + %.2lf = %.2lf",firstNumber, secondNumber, firstNumber + secondNumber);
            break;

        case '-':
            printf("%.2lf - %.2lf = %.2lf",firstNumber, secondNumber, firstNumber - secondNumber);
            break;

        case '*':
            printf("%.2lf * %.2lf = %.2lf",firstNumber, secondNumber, firstNumber * secondNumber);
            break;

        case '/':
            printf("%.2lf / %.2lf = %.2lf",firstNumber, secondNumber, firstNumber / secondNumber);
            break;

        // operator doesn't match any case constant (+, -, *, /)
        default:
            printf("Error! operator is not correct");
    }
   
    return 0;
 
}

}
bitis:
cout<<"\nDevam etmek için [Y] /Programdan çıkmak icin herhangi başka bir tuşa basınız\n\nDevam etmek istiyormusnuz?";
cin>> cevap;
 
if (cevap == 'y')
{
goto baslangic;
}
else
system ("PAUSE");
return EXIT_SUCCESS;
}

printf("%.2lf % %.2lf = %.2lf",firstNumber, secondNumber, firstNumber % secondNumber);