1、第六章課后習(xí)題答案（第二版譚浩強）1:/xt6-1/cpp#include <iostream> /如用VC+應(yīng)改為#include <>using namespace std; /如用VC+應(yīng)取消此行#include ""#include ""#include ""#include ""int main()Cylinder cy1,10); cout<<"noriginal cylinder:nx="<<()<<", y=&

2、quot;<<()<<", r="<<()<<", h="<<()<<"narea="<<()<<", volume="<<()<<endl; (15); ; (5,5); cout<<"nnew cylinder:n"<<cy1; Point &pRef=cy1; cout<<"npRef as a point:"

3、;<<pRef; Circle &cRef=cy1; cout<<"ncRef as a Circle:"<<cRef; return 0;3:解法一#include <iostream>using namespace std;class Pointpublic: Point(float a,float b):x(a),y(b) Point()cout<<"executing Point destructor"<<endl; private: float x; float y

4、;class Circle:public Pointpublic: Circle(float a,float b,float r):Point(a,b),radius(r) Circle()cout<<"executing Circle destructor"<<endl; private: float radius;int main()Point *p=new Circle,; delete p; return 0;3：解法二#include <iostream>using namespace std;class Pointpublic

5、: Point(float a,float b):x(a),y(b) Point()cout<<"executing Point destructor"<<endl; private: float x; float y;class Circle:public Pointpublic:Circle(int a,int b,int r):Point(a,b),radius(r) Circle()cout<<"executing Circle destructor"<<endl; private: float r

6、adius;int main()Point *p=new Circle,; Circle *pt=new Circle,; delete pt; return 0;3：解法三#include <iostream>using namespace std;class Pointpublic: Point(float a,float b):x(a),y(b) virtual Point()cout<<"executing Point destructor"<<endl; private: float x; float y;class Circl

7、e:public Pointpublic:Circle(float a,float b,float r):Point(a,b),radius(r) virtual Circle()cout<<"executing Circle destructor"<<endl; private:float radius;void main()Point *p=new Circle,; delete p;4：#include <iostream>using namespace std;/定義抽象基類Shapeclass Shapepublic: virt

8、ual double area() const =0; /純虛函數(shù);/定義Circle類class Circle:public Shapepublic:Circle(double r):radius(r) /結(jié)構(gòu)函數(shù) virtual double area() const return *radius*radius; /定義虛函數(shù) protected: double radius; /半徑;/定義Rectangle類class Rectangle:public Shapepublic: Rectangle(double w,double h):width(w),height(h) /結(jié)構(gòu)函數(shù)

9、virtual double area() const return width*height; /定義虛函數(shù)protected: double width,height; /寬與高;class Triangle:public Shapepublic: Triangle(double w,double h):width(w),height(h) /結(jié)構(gòu)函數(shù) virtual double area() const return *width*height; /定義虛函數(shù) protected: double width,height; /寬與高;/輸出面積的函數(shù)void printArea(con

10、st Shape &s)cout<<()<<endl; /輸出s的面積int main() Circle circle; /建立Circle類對象circle cout<<"area of circle =" printArea(circle); /輸出circle的面積 Rectangle rectangle,; /建立Rectangle類對象rectangle cout<<"area of rectangle =" printArea(rectangle); /輸出rectangle的面積 Tr

11、iangle triangle,; /建立Triangle類對象 cout<<"area of triangle =" printArea(triangle); /輸出triangle的面積 return 0;5：#include <iostream>using namespace std;/定義抽象基類Shapeclass Shapepublic: virtual double area() const =0; /純虛函數(shù);/定義Circle(圓形)類class Circle:public Shapepublic:Circle(double r):

12、radius(r) /結(jié)構(gòu)函數(shù) virtual double area() const return *radius*radius; /定義虛函數(shù) protected: double radius; /半徑;/定義Square(正方形)類class Square:public Shapepublic: Square(double s):side(s) /結(jié)構(gòu)函數(shù) virtual double area() const return side*side; /定義虛函數(shù) protected: double side;/定義Rectangle(矩形)類class Rectangle:public S

13、hapepublic: Rectangle(double w,double h):width(w),height(h) /結(jié)構(gòu)函數(shù) virtual double area() const return width*height; /定義虛函數(shù) protected: double width,height; /寬與高;/定義Trapezoid(梯形)類class Trapezoid:public Shapepublic: Trapezoid(double t,double b,double h):top(t),bottom(t),height(h) /結(jié)構(gòu)函數(shù) virtual double ar

14、ea() const return *(top+bottom)*height; /定義虛函數(shù) protected: double top,bottom,height; /上底、下底與高;/定義Triangle(三角形)類class Triangle:public Shapepublic: Triangle(double w,double h):width(w),height(h) /結(jié)構(gòu)函數(shù) virtual double area()const return *width*height; /定義虛函數(shù) protected: double width,height; /寬與高;int main() Circle circle; /建立Circle類對象circle Square square; /建立Square類對象square Rectangle rectangle,; /建立Rectangle類對象rectangle Trapezoid trapezoid,; /建立Trapezoid類對象trapezoid Triangle triangle,; /建立Triangle類對象 Shape *pt5=&circle,&square,&re