C++面向对象程序设计第六章课后习题答案第2版谭浩强.docx

1、C+面向对象程序设计第六章课后习题答案第2版谭浩强C+面向对象程序设计第六章课后习题答案(第2版谭浩强)第六章课后习题答案（第二版谭浩强）1:/xt6-1/cpp#include /如用VC+应改为#include using namespace std; /如用VC+应取消此行#include cylinder.h#include point.cpp#include circle.cpp#include cylinder.cppint main()Cylinder cy1(3.5,6.4,5.2,10); coutnoriginal cylinder:nx=cy1.getX(), y=cy1

2、.getY(), r=cy1.getRadius(), h=cy1.getHeight()narea=cy1.area float y;class Circle:public Pointpublic:Circle(int a,int b,int r):Point(a,b),radius(r) Circle()coutexecuting Circle destructorendl; private: float radius;int main()Point *p=new Circle(2.5,1.8,4.5); Circle *pt=new Circle(2.5,1.8,4.5); delete

3、 pt; return 0;3：解法三#include using namespace std;class Pointpublic: Point(float a,float b):x(a),y(b) virtual Point()coutexecuting Point destructorendl; private: float x; float y;class Circle:public Pointpublic:Circle(float a,float b,float r):Point(a,b),radius(r) virtual Circle()coutexecuting Circle d

4、estructorendl; private:float radius;void main()Point *p=new Circle(2.5,1.8,4.5); delete p;4：#include using namespace std;/定义抽象基类Shapeclass Shapepublic: virtual double area() const =0; /纯虚函数;/定义Circle类class Circle:public Shapepublic:Circle(double r):radius(r) /结构函数 virtual double area() const return

5、3.14159*radius*radius; /定义虚函数 protected: double radius; /半径;/定义Rectangle类class Rectangle:public Shapepublic: Rectangle(double w,double h):width(w),height(h) /结构函数 virtual double area() const return width*height; /定义虚函数protected: double width,height; /宽与高;class Triangle:public Shapepublic: Triangle(d

6、ouble w,double h):width(w),height(h) /结构函数 virtual double area() const return 0.5*width*height; /定义虚函数 protected: double width,height; /宽与高;/输出面积的函数void printArea(const Shape &s)couts.area()endl; /输出s的面积int main() Circle circle(12.6); /建立Circle类对象circle coutarea of circle =; printArea(circle); /输出ci

7、rcle的面积 Rectangle rectangle(4.5,8.4); /建立Rectangle类对象rectangle coutarea of rectangle =; printArea(rectangle); /输出rectangle的面积 Triangle triangle(4.5,8.4); /建立Triangle类对象 coutarea of triangle =; printArea(triangle); /输出triangle的面积 return 0;5：#include using namespace std;/定义抽象基类Shapeclass Shapepublic:

8、virtual double area() const =0; /纯虚函数;/定义Circle(圆形)类class Circle:public Shapepublic:Circle(double r):radius(r) /结构函数 virtual double area() const return 3.14159*radius*radius; /定义虚函数 protected: double radius; /半径;/定义Square(正方形)类class Square:public Shapepublic: Square(double s):side(s) /结构函数 virtual d

9、ouble area() const return side*side; /定义虚函数 protected: double side;/定义Rectangle(矩形)类class Rectangle:public Shapepublic: Rectangle(double w,double h):width(w),height(h) /结构函数 virtual double area() const return width*height; /定义虚函数 protected: double width,height; /宽与高;/定义Trapezoid(梯形)类class Trapezoid:

10、public Shapepublic: Trapezoid(double t,double b,double h):top(t),bottom(t),height(h) /结构函数 virtual double area() const return 0.5*(top+bottom)*height; /定义虚函数 protected: double top,bottom,height; /上底、下底与高;/定义Triangle(三角形)类class Triangle:public Shapepublic: Triangle(double w,double h):width(w),height(

11、h) /结构函数 virtual double area()const return 0.5*width*height; /定义虚函数 protected: double width,height; /宽与高;int main() Circle circle(12.6); /建立Circle类对象circle Square square(3.5); /建立Square类对象square Rectangle rectangle(4.5,8.4); /建立Rectangle类对象rectangle Trapezoid trapezoid(2.0,4.5,3.2); /建立Trapezoid类对象trapezoid Triangle triangle(4.5,8.4); /建立Triangle类对象 Shape *pt5=&circle,&square,&rectangle,&trapezoid,▵ /定义基类指针数组pt，使它每一个元素指向一个派生类对象 double areas=0.0; /areas为总面积 for(int i=0;iarea(); couttotol of all areas=areasendl; /输出总面积 return 0;