C++实验19

一、坐标到圆到圆柱

#include<iostream>using namespace std;#define pi 3.1415926class point{    float x;    float y;public:    point(int a=0, int b=0) {x=a;y=b;cout<<"point constructor\n";}    ~point()           {cout<<"point destructor\n";}    void display_point()    {        cout<<"x="<<x<<"\ty="<<y<<endl;    }};class circle:public point{    float r;public:    circle(float a=0,float b=0,float c=0):point(a,b)    {        r=c;        cout<<"circle constructor"<<endl;    }    ~circle(){cout<<"circle destructor"<<endl;}    float getr(){return r;}    float area();    void display_circle();};float circle::area() {return r*r*pi;}void circle::display_circle() {    display_point();    cout<<"r="<<r<<endl;}class cylinder:public circle{    float hight;public:    cylinder(float a=0, float b=0,float c=0, float d=0):circle(a,b,c)    {        hight=d;        cout<<"cylinder consturctor"<<endl;    }    ~cylinder(){cout<<"cylinder destructor"<<endl;}    float volume() {return area()*hight;}    void display()    {        display_circle();        cout<<"hight="<<hight<<endl;    }};void main(){    cylinder a(1,2,3,4);    a.display();}

二、学生类派生

#include<iostream>#include<string.h>class student{    int id;    char name[20];    char sex[6];    int age;public:    student(int a,char *b, char *c, int d)    {        id=a;strcpy(name,b);strcpy(sex,c);age=d;        std::cout<<"student constructor\n";    }    ~student(){std::cout<<"student destructor\n";}    void print_student();};class phd: public student{    int papernum;    float workhour;public:    phd(int a, char *b, char *c, int d,int e, float f):student(a,b,c,d)    {        papernum=e;        workhour=f;        std::cout<<"phd constructor\n";    }    ~phd(){std::cout<<"phd destructor\n";}    void print_phd();};class master: public student{    float grade;    int flag;public:    master(int a, char *b, char *c, int d, float e, int f):student(a,b,c,d)    {        grade=e;        flag=f;        std::cout<<"master constructor\n";    }    ~master(){std::cout<<"master destructor\n";}    void print_master();};class undergraduate: public student{    float gradein;    float gradeout;public:    undergraduate(int a, char *b, char *c, int d, float e, float f):student(a,b,c,d)    {        gradein=e;        gradeout=f;        std::cout<<"undergraduate destructor\n";    }    ~undergraduate(){std::cout<<"undergraduate destructor\n";}    void print_undergraduate();};void student::print_student(){    std::cout<<"idnumber: "<<id<<"\nname: "<<name<<"\nsex: "<<sex<<"\nage: "<<age<<'\n';}void phd::print_phd(){    print_student();    std::cout<<"paper number: "<<papernum<<"\nworking hours: "<<workhour<<'\n';}void master::print_master(){    print_student();    std::cout<<"grade: "<<grade<<"\nattending? ";    if(flag)        std::cout<<"yes\n";    else        std::cout<<"no\n";}void undergraduate::print_undergraduate(){    print_student();    std::cout<<"incourse grade: "<<gradein<<"\noutcourse grade: "<<gradeout<<'\n';}void main(){    phd a(12345678,"张三","男",25,3,20);    master b(2234567,"李四","女",24,98,0);    undergraduate c(32345678,"赵五","男",23,100,100);    a.print_phd();    std::cout<<'\n';    b.print_master();    std::cout<<'\n';    c.print_undergraduate();}