c++程序设计题.docx

六、程序设计题(本大题共1小题，共10分)1. 已定义一个Shape抽象类，在此基础上派生出矩形Rectangle和圆形Circle类，二者都有GetPerim（）函数计算对象的周长，并编写测试main（）函数。class Shapepublic:Shape()Shape()virtual float GetPerim()=0;答案：class Rectangle:public Shapepublic:Rectangle(float i,float j):L(i),W(j)Rectangle()float GetPerim()return 2*(L+W);private:float L,W;class Circle:public Shapepublic:Circle(float r):R(r)float GetPerim()return 3.14*2*R;private:float R;void main()Shape * sp;sp=new Circle(10);coutGetPerim ()endl;sp=new Rectangle(6,4);coutGetPerim()endl;_六、程序设计题(本大题共1小题，共10分)1. 编写类String的构造函数、析构函数和赋值函数和测试程序。已知类String的原型为：#include #include class Stringpublic:String(const char *str=NULL); / 普通构造函数String(const String &other); / 拷贝构造函数String(); / 析构函数String & operator=(const String &other); / 赋值函数void show()coutm_datawheels=wheels;this-weight=weight;coutwheelsendl;int vehicle:get_wheels()return wheels;float vehicle:get_weight()return weight;void vehicle:print()cout车轮数：wheels,重量：weightendl;答案：class car:public vehicleprivate:int passengers;public:void init(int wheels,float weight,int pass);int getpassenger();void print();；void car:init(int wheels,float weight,int pass)vehicle:init(wheels,weight);passengers=pass;int car:getpassenger()return passengers;void car:print()vehicle:print();cout可载人数：passengersendl;_六、程序设计题（本大题共1小题，共10分）1. 求n(n=3)个学生的最高分和最低分及姓名，已有student类声明和main函数，完成student类的实现部分。#include #include class studentchar name10;int deg;public:student(char na=,int d=0);char * getname();friend int compare(student &s1,student &s2);int getdeg();void main()student st=student(王强,74),student(李刚,68),student(张雪,84);int i=0,min=0,max=0;for(i=1;i3;i+)if(compare(stmax,sti)=-1)max=i;if(compare(stmin,sti)=1)min=i;cout最高分：stmax.getdeg()姓名:stmax.getname()endl;cout最低分:(*(st+min).getdeg()姓名:stmax.getname()s2.deg)return 1;else if(s1.deg=s2.deg)return 0;else return -1;int student:getdeg()return deg;_六、程序设计题（本大题共1小题，共10分）1. 写一个程序，定义一个抽象类Shape,由它派生3个类：Square(正方形)、Trapezoid（梯形）和Triangle三角形。用虚函数分别计算几种图形面积、并求它们的和。要求用基类指针数组，使它每一个元素指向一个派生类对象。#include class Shapepublic:virtual double area()const=0;答案：class Square:public Shapepublic:Square(double s):side(s)double area() constreturn side*side;private:double side;class Trapezoid:public Shapepublic:Trapezoid(double i,double j,double k):a(i),b(j),h(k)double area() constreturn (a+b)*h/2);private:double a,b,h;class Triangle:public Shapepublic:Triangle(double i,double j):w(i),h(j)double area() constreturn(w*h/2);private:double w,h;void main()Sh