C++程序设计考试题及答案

C++程序设计1、声明个CPU类，包含等级(rank)，频率（frequency），电压（voltage）属性，有两个公有成员函数run（函数功能：输出“cpu正在运行”），stop（函数功能：输出“cpu停止运行”）。

其中rank为枚举型CPU_Rank，声明为enumCPU_Rank{P1=1,P2,P3,P4,P5,P6,P7},frequency为单位是MHz的整型数，voltage为double 型电压值。

编写构造函数和析构函数，在主函数中显示它们的调用顺序。

2、定义复数类COMPLEX，并用成员函数为复数类COMPLEX重载加、减及赋值运算符操作。

3、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。

4、已知交通工具类定义如下。

要求：（1)实现这个类；（2）定义并实现一个小车类car，是它的公有派生类，小车本身的私有属性有载人数，小车的函数有init(设置车轮数，重量和载人数），getpassenger(获取载人数)，print（打印车轮数，重量和载人数）。

5、声明一个车（vehicle）基类，具有maxspeed、weight成员变量，run、stop成员函数（简单输出提示“车正在行进”，“车停止”），由此派生出自行车类（bicycle）、汽车类（motorcar）。

自行车类有高度（height）属性，汽车(motorcar) 类有座位数(seatnum)。

从bicycle和motorcar 派生出摩托车类(motorcycle)，在继承过程中，注意把vehicle 设置为虚基类，同时编写各个类的构造函数和析构函数，在主函数中建立各个类对象，观察执行情况。

6、定义类X、Y、Z，函数h(X *),满足：类X有私有成员i,Y的成员函数g(X *)是X的友元函数，实现对X的成员i加1;类Z是类X的友元类，其成员函数f(X *)实现对X的成员i加5；函数h(X *)是X的友元函数，实现对X的成员i加10。

在一个文件中定义和实现类，在另一个文件中实现main()函数。

提示：按Y、Z、X顺序定义类，在Y、Z类前前向声明X ， X * x表示X类对象指针x，访问x对象数据成员i变量的形式为 x->i。

答案1、#include <iostream.h>enum CPU_Rank {P1=1,P2,P3,P4,P5,P6,P7};class CPU{private:CPU_Rank rank;int frequency;float voltage;public:void run();void stop();CPU(CPU_Rank r,int f,float v);~CPU();CPU(CPU &c);};void CPU::run(){cout<<"CPU正在运行"<<endl;}void CPU::stop(){cout<<"CPU停止运行"<<endl;}（1分）CPU::CPU(CPU_Rank r,int f,float v){rank=r;frequency=f;voltage=v;cout<<"构造了一个CPU:"<<endl;}CPU::~CPU(){cout<<"析构了一个CPU:"<<endl;}void main(){CPU a(P1,300,2.8);a.run();a.stop();}2、class COMPLEX {public:COMPLEX(double r = 0, double i = 0);COMPLEX operator +(const COMPLEX& other); COMPLEX operator -(const COMPLEX& other); COMPLEX operator =(const COMPLEX& other); private:double real, image; // 复数的实部与虚部};COMPLEX::COMPLEX(double r, double i){real=r;image=I;}COMPLEX::COMPLEX operator +(const COMPLEX& other) { COMPLEX temp;temp.real=real+other.real;temp.image=image+other.image;return temp}COMPLEX::COMPLEX operator -(const COMPLEX& other) { COMPLEX temp;temp.real=real-other.real;temp.image=image-other.image;return temp}COMPLEX::COMPLEX operator =(const COMPLEX& other){real=other.real;image=other.image;return *this;}3、class vehicle{protected:int wheels;//车轮数float weight;//重量public:void init(int wheels,float weight);int get_wheels();float get_weight();void print();};void vehicle::init(int wheels,float weight){this->wheels=wheels;this->weight=weight;cout<<wheels<<endl;}int vehicle::get_wheels(){return wheels;}float vehicle::get_weight(){return weight;}void vehicle::print(){cout<<"车轮数："<<wheels<<","<<"重量："<<weight<<endl;} class car:public vehicle{private: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："<<passengers<<endl;}4、#include <iostream.h>class Shape{public:virtual double area()const=0;};class Square:public Shape{public:Square(double s):side(s){}double area() const{return side*side;}private:double side;};class Trapezoid:public Shape{public:Trapezoid(double i,double j,double k):a(i),b(j),h(k) {}double area() const{return ((a+b)*h/2);}private:double a,b,h;};class Triangle:public Shape{public:Triangle(double i,double j):w(i),h(j){}double area() const{return(w*h/2);}private:double w,h;};void main(){Shape *p［5］;Square se(5);Trapezoid td(2,5,4);Triangle te(5,8);p［0］=&se;p［1］=&td;p［2］=&te;double da=0;for(int i=0;i<3;i++){da+=p［i］->area();}cout<<"总面积是："<<da<<endl;}5、#include <iostream.h>class vehicle{private:int maxspeed;int weight;public:vehicle(int m,int w){maxspeed=m;weight=w;cout<<"vehicle构造函数"<<endl;}~vehicle(){cout<<"vehicle析构函数"<<endl;}void run(){cout<<"车在行进中……"<<endl;}void stop(){cout<<"车停止"<<endl;}};class bicycle:virtual public vehicle{private:double height;public:bicycle(int m,int w,double h):vehicle(m,w){height=h;cout<<"bicycle构造函数"<<endl;}~bicycle(){cout<<"bicycle析构函数"<<endl;}};class motorcar:virtual public vehicle{private:int seatnum;public:motorcar(int m,int w,int s):vehicle(m,w){seatnum=s;cout<<"motorcar构造函数"<<endl;}~motorcar(){cout<<"motorcar析构函数"<<endl;}};class motorcycle:public bicycle,public motorcar{public:motorcycle(int m,int w,double h,int s):bicycle(m,w,h),motorcar(m,w,s),vehicle(m,w){cout<<"motorcycle构造函数"<<endl;}~motorcycle(){cout<<"motorcycle析构函数"<<endl;} };void main(){vehicle a(200,3);a.run();a.stop();bicycle b(50,1,1.5);b.run();b.stop();motorcar c(120,2,5);c.run();c.stop();motorcycle d(100,1,1.3,3);d.run();d.stop();}6、#include <iostream.h>class X;class Y{public:void g(X* x);};class Z{public:void f(X* x);};class X{private:int i;public:friend void Y::g(X*);friend class Z;friend void h(X*);X(int i1){i=i1;cout<<"在X类中i的值是:"<<i<<endl;} };void Y::g(X *x){x->i++;cout<<"在Y类中i的值是:"<<x->i<<endl;}void Z::f(X *x){x->i+=5;cout<<"在Z类中i的值是:"<<x->i<<endl;}void h(X *x){x->i+=10;cout<<"在函数h中i的值是:"<<x->i<<endl;}int main(){X x(1);Y y;Z z;y.g(&x);z.f(&x);h(&x);}。