写一个程序，定义抽象基类container 由它派生出3个派生类， sphere(球体)，cylinder(圆柱体)cube（正方体） 用虚函数分别计算几种

[不知所措的小可爱]

写一个程序，定义抽象基类container 由它派生出3个派生类， sphere(球体)，cylinder(圆柱体)cube（正方体） 用虚函数分别计算几种图形的表面积和体积 此外，编写重载运算符函数，重载运算符>和<用于判断对象的大小。如b1>b2,返回值为真或者假。 大神能帮我看看，我的代码有什么问题吗？ #include<iostream.h> class Container { protected: double r; double l; public: Container(double x=0,double y=0) { r=x; l=y; } virtual int area()=0;//表面积 virtual int volume()=0;//体积 virtual int show()=0; }; class Sphere:public Container{ public: Sphere(double x=0,double y=0):Container(x,y) {}; int area() { cout<<"这个球体的表面积:"<<4*3.14*r*r<<endl; return 0; } int volume() { cout<<"这个球体的体积："<<(4.0/3)*3.14*r*r*r<<endl; return 0; } int show() { cout<<area()<<endl; cout<<volume()<<endl; return 0; } int operator>(Sphere& a,Sphere& b) { int i; if(a.area()>b.area()) i=1; else if(a.volume()>b.volume()) i=1; else i=0; return i; } int operator<(Sphere& a,Sphere& b) { int i; if(a.area()<b.area()) i=1; else if(a.volume()<b.volume()) i=1; else i=0; return i; } };//球体 class Cylinder:public Container{ public: Cylinder(double x=0,double y=0):Container(x,y) {}; int area() { cout<<"这个圆柱体的表面积:"<<2*3.14*r*r+2*3.14*r*l<<endl; return 0; } int volume() { cout<<"这个圆柱体的体积:"<<3.14*r*r*l<<endl; return 0; } int show() { cout<<area()<<endl; cout<<volume()<<endl; return 0; } int operator>(Cylinder& a,Cylinder& b) { int i; if(a.area()>b.area()) i=1; else if(a.volume()>b.volume()) i=1; else i=0; return i; } int operator<(Cylinder& a,Cylinder& b) { int i; if(a.area()<b.area()) i=1; else if(a.volume()<b.volume()) i=1; else i=0; return i; } };//圆柱体 class Cube:public Container{ public: Cube(double x=0,double y=0):Container(x,y) {}; int area() { cout<<"这个正方体的表面积:"<<6*r*r<<endl; return 0; } int volume() { cout<<"这个正方体的体积:"<<r*r*r<<endl; return 0; } int show() { cout<<area()<<endl; cout<<volume()<<endl; return 0; } int operator>(Cube& a,Cube& b) { int i; if(a.area()>b.area()) i=1; else if(a.volume()>b.volume()) i=1; else i=0; return i; } int operator<(Cube& a,Cube& b) { int i; if(a.area()<b.area()) i=1; else if(a.volume()<b.volume()) i=1; else i=0; return i; } };//正方体 int main() { Container *ptr; Sphere b1(5.0),b2(4.0),b3,b4; Cylinder c1(5.0,4.0),c2(4.0,7.0); Cube c3(5.0),c4(6.0); ptr=&b1; ptr->area(); ptr->volume(); ptr=&b2; ptr->area(); ptr->volume(); int i; i=(b1>b2); if(i==1) { cout<<b1.area()<<">"<<b2.area()<<"ture"<<endl; cout<<b1.volume()<<">"<<b2.volume()<<"ture"<<endl; } else { cout<<b1.area()<<"<"<<b2.area()<<"false"<<endl; cout<<b1.volume()<<"<"<<b2.volume()<<"false"<<endl; } /*ptr=&c1; ptr->area(); ptr->volume(); ptr=&c2; ptr->area(); ptr->volume(); ptr=&c3; ptr->area(); ptr->volume(); ptr=&c4; ptr->area(); ptr->volume();*/ return 0; }

[Italink]

重载符号有两种方式，你用的是方法2，前面加friend，定义友元函数<,另外有个小瑕疵就是返回值应该是bool类型 bool operator>(Cylinder& a) {}//方法1：拿this和a比较 friend bool operator>(Cylinder& a, Cylinder& b) {} //方法2：在类外拿两个Cylinder对象比较

[Moshangxue]

#include <iostream> using namespace std; class Container { public: virtual double area()=0;//表面积 virtual double volume()=0;//体积 virtual void show()=0; }; class Sphere:public Container { private: double r; public: Sphere(double x=0) {r=x;} virtual double area() { return 4*3.14*r*r; } virtual double volume() { return (4.0/3)*3.14*r*r*r; } virtual void show() { cout<<"表面积:"<<area()<<endl; cout<<"体积："<<volume()<<endl; } friend bool operator>(Sphere& a,Sphere& b) { bool i; if(a.area()>b.area()) i=1; else if(a.volume()>b.volume()) i=1; else i=0; return i; } friend bool operator<(Sphere& a,Sphere& b) { bool i; if(a.area()<b.area()) i=1; else if(a.volume()<b.volume()) i=1; else i=0; return i; } };//球体 int main() { Container *ptr[2]; Sphere b1(5.0),b2(4.0); ptr[0]=&b1; ptr[1]=&b2; cout<<"球体1:";ptr[0]->show(); cout<<"球体2:";ptr[1]->show(); int i; i=(b1>b2); if(i==1) { cout<<b1.area()<<">"<<b2.area()<<":ture"<<endl; cout<<b1.volume()<<">"<<b2.volume()<<":ture"<<endl; } else { cout<<b1.area()<<"<"<<b2.area()<<":false"<<endl; cout<<b1.volume()<<"<"<<b2.volume()<<":false"<<endl; } return 0; }

[Moshangxue]

错误很多，与其把体积表面积定义为int类型函数，返回一个0，没用啊，还不如void