int main() {
ConcreteSubject * subject = new ConcreteSubject();
subject->Attach(new ConcreteObserver(subject, "zhaohua"));
subject->Attach(new ConcreteObserver(subject, "lichao"));
subject->SetState("Doc Yang comes here !!!");
subject->Notify();
return 0;
}
int main()
{
ConcreteSubject product;
ConcObs shop1("Shop 1");
ConcObs shop2("Shop 2");
ConcObs shop2("Shop 3");
product.Attach(&shop1);
product.Attach(&shop2);
product.Attach(&shop3);
product.ChangePrice(23.0f);
product.Detach(&shop2);
product.ChangePrice(26.0f);
return 0;
}