#include <iostream>
 
using namespace std;
 
int main()
{
 
    int x, y, z;
    char math_operator, exit_app;
    int startover(char& exit_app);
    int calculation(int x, int y, int& z, char math_operator);
 
 
        cout << "(x ? y) - Please your first number followed by a space, then a legal math operator, followed by a space, then your second number. - (x ? y):  ";
        cin >> x >> math_operator >> y;
 
        while ((math_operator = '/') && (y == 0))
        {
            cout << "Error:  Cannot divide by zero." << endl;
            cout << "Please re enter a legal math operator ( Supported: Addition(+), Subtraction(-), Multiplication(*), Divide(/) ):  ";
            cin << math_operator;
        }
 
        while ((math_operator != '+') (math_operator != '-') (math_operator != '*') (math_operator != '/'))
        {
            cout << "You have not entered a supported math operator." << endl;
            cout << "Please enter a legal math operator:  ";
            cin >> math_operator;
        }
 
        calculation(x, y, z, math_operator);
 
        cout << x << " " << math_operator << " " << y << " = " << z << endl;
 
        startover(exit_app);
 
 
}
 
 
 
int calculation(int x, int y, int& z, char math_operator)
{
 
    switch (math_operator)
    {
    case '+': z = x + y; break;
    case '-': z = x - y; break;
    case '*': z = x * y; break;
    case '/': z = x / y; break;
    }
 
    return z;
 
}
 
int startover(char& exit_app)
{
 
    cout << "Thank you for using my program!" << endl;
    cout << "Would you like to start over? ( s = start over, q = quit ):  ";
    cin >> exit_app;
 
    switch (exit_app)
    {
 
    case 's': main()
    case 'q': cout << "Have a nice day!" << endl;
 
    }
 
    cin.get()
 
}