c++ primer 第五章习题

int _tmain(int argc, _TCHAR* argv[])
{
int a, b;
while (cin >> a >> b)
{
try
{
if (b == 0)
throw runtime_error("second num should not be 0.");
cout << "result of a/b is " << ((double)a) / b << endl;
}
catch (runtime_error err)
{
cout << err.what();
cout << "\nwant input again? enter n to exit, other to continue" << endl;
char c;
cin >> c;
if (!cin || c == 'n')
break;
}
}
return 0;
}