C++实现观察者模式—2

多个主题对象，每个主题对象都有三个观察者，感觉有点问题，说不好。有问题请提出来。

/*观察者模式：定义一种一对多的依赖，让多个观察者同时观察一个对象，当对象状态发生变化时，会通知所有它的观察者*/#include <iostream>#include <list>#include <string>using namespace std;class Subject;class Observer{protected:string name;Subject *subject;public:Observer(Subject *subject, string name){this->subject = subject;this->name = name;}virtual void Update(){}};class Subject{list<Observer*> observers;public:void AddObserver(Observer *observer){observers.push_back(observer);}void RemoveObserver(Observer *observer){observers.remove(observer);}virtual void Notify(){list<Observer*>::iterator iter = observers.begin();for(; iter != observers.end(); iter++){(*iter)->Update();}}virtual string  GetState(){return " ";}int GetObserverSize(){return observers.size();}};class ConcreteSubjectOne:public Subject{string state;public:ConcreteSubjectOne(string state){this->state ="One " + state;}string GetState(){return this->state;}};class ConcreteSubjectTwo:public Subject{string state;public:ConcreteSubjectTwo(string state){this->state ="Two " + state;}string GetState(){return this->state;}};class ConcreteObserverOne:public Observer{public:ConcreteObserverOne(Subject *subject, string name):Observer(subject, name){}void Update(){cout<<"Observer Type One: "<< name << " subject state is "<< subject->GetState()<<endl;}};class ConcreteObserverTwo:public Observer{public:ConcreteObserverTwo(Subject *subject, string name):Observer(subject, name){}void Update(){cout<<"Observer Type Two: "<< name << " subject state is "<< subject->GetState()<<endl;}};int main(){ConcreteSubjectOne *subject_1 = new ConcreteSubjectOne("subject__1");ConcreteSubjectTwo *subject_2 = new ConcreteSubjectTwo("subject__2");ConcreteObserverOne *observer1  = new ConcreteObserverOne(subject_1, "observer 1");ConcreteObserverOne *observer2  = new ConcreteObserverOne(subject_1, "observer 2");ConcreteObserverOne *observer3  = new ConcreteObserverOne(subject_1, "observer 3");ConcreteObserverTwo *observer4  = new ConcreteObserverTwo(subject_2, "observer 4");ConcreteObserverTwo *observer5  = new ConcreteObserverTwo(subject_2, "observer 5");ConcreteObserverTwo *observer6  = new ConcreteObserverTwo(subject_2, "observer 6");subject_1->AddObserver(observer1);subject_1->AddObserver(observer2);subject_1->AddObserver(observer3);subject_2->AddObserver(observer4);subject_2->AddObserver(observer5);subject_2->AddObserver(observer6);subject_1->Notify();subject_2->Notify();cout<<subject_1->GetObserverSize()<<endl;cout<<subject_2->GetObserverSize()<<endl;delete subject_1;delete subject_2;delete observer6;delete observer5;delete observer4;delete observer3;delete observer2;delete observer1;getchar();return 0;}