// a simple calculator using switch
int main()
{ int x,y;
  char op;
  cout<<"Enter an equation (Example 12*5):";
  cin>>x>>op>>y;   //use cin to read all 3 variables
  switch (op)
  { case '+': cout<<x+y; break;
    case '-': cout<<x-y; break;
    case '*': cout<<x*y; break;
    case '/': // don't try to divide by zero!!! 
      if (y==0) cout<<"Divide by zero not allowed.\n";
      else cout<<x/(y*1.0); //force result as double
      break;
    case '%': cout<<x%y; break;
    default: cout<<op<<" is not a valid operator.\n";
  } //switch op
  return 0;
} // main