//第一节的内容是多重继承，由于前面在继承那一章已经粗略地了解了多种继承，所以本节及后面几节主要是说明"为什么要使用多重继承"/*#include 
     
      using namespace std;class father{public:	void smart()	{	   cout<<"父亲很聪明"<
      
       >choice;		switch(choice)		{		case 0:			quit = true;			break;		case 1:			pf = new father;			pf->beautiful();			break;		case 2:			pf = new son;			pf->beautiful();			pf->smart();			delete pf;			break;		default:			cout<<"请输入从0到2之间的数字"<
       
        using namespace std;class father{public:	void smart()	{	   cout<<"父亲很聪明"<
        
         >choice;		switch(choice)		{		case 0:			quit = true;			break;		case 1:			pf = new father;			//pf->beautiful();			break;		case 2:			pf = new son;			//pf->beautiful(); //father类已经没有beautiful()函数，所以这里不能访问			//只能用指针转换			dynamic_cast
         
          (pf)->beautiful();			//因此我们必须将基类指针强制转换为子类指针，这里要用到一个方法--dynamic_cast			//dynacic_cast的作用是对不同类之间的数据类型进转换，它可一个基类的指针转换成一个派生类的指针			pf->smart();			delete pf;			break;		default:			cout<<"请输入从0到2之间的数字"<
          
           using namespace std;class father{public: void smart() { cout<<"父亲很聪明"<
           
            >choice; switch(choice) { case 0: quit = true; break; case 1: pf = new father; break; case 2: pm = new son; pm->beautiful(); delete pm; break; default: cout<<"请输入从0到2之间的数字"<
            
             using namespace std;class Human{public: Human(){cout<<"构造Human"<
             
              >choice; switch(choice) { case 0: quit = true; break; case 1: p = new father; p->beautiful(); delete p; break; case 2: p = new son; //这里产生了两义性，因为父亲和母亲类都是从人类来的，一分是从母类，一分是从父类 p->beautiful(); p->smart(); delete p; break; case 3: p = new mother; p->beautiful(); delete p; default: cout<<"请输入从0到2之间的数字"<
              
               using namespace std;class Human{public: Human(){cout<<"构造Human"<
               
                >choice; switch(choice) { case 0: quit = true; break; case 1: p = new father; p->beautiful(); p->smart(); delete p; break; case 2: p = new son; //这里产生了两义性，因为父亲和母亲类都是从人类来的，一分是从母类，一分是从父类 p->beautiful(); p->smart(); delete p; break; case 3: p = new mother; p->beautiful(); p->smart(); delete p; default: cout<<"请输入从0到2之间的数字"<
                
                 using namespace std;class Shape{public: virtual double area()=0;};//三角形class Trigon: public Shape{protected: double h, w;public: Trigon(double H, double W) { h = H; w = W; } double area() { return h * w / 2; };};//正方形class Square : public Trigon{public: Square(double H, double W):Trigon(H, W) { } double area(){return h*w;}};//圆class Circle: public Shape{protected: double radius;public: Circle(double r){radius = r;} double area(){ return radius * radius * 3.14; }};int main(){ Shape *p; int choice = 0; while(1) { bool quit = false; cout<<"(0)退出 (1)三角形 (2)正方形 (3)圆"<
                 
                  >choice; switch(choice) { case 0: quit = true; break; case 1: p = new Trigon(5.0,6.0); cout<<"三角形的面积是:"<
                  
                   area()<
                   
                    area()<
                    
                     area()<
                     
                       0){ delete p; } if(quit == true){ break; } }; return 0;}*/