实验5 继承和多态

task1

代码

 1 #pragma once
 2 #include <iostream>
 3 #include <string>
 4 using std::cout;
 5 using std::endl;
 6 using std::string;
 7 // 发行/出版物类：Publisher （抽象类）
 8 class Publisher {
 9 public:
10     Publisher(const string &s = "");            // 构造函数
11 public:
12     virtual void publish() const = 0;                 // 纯虚函数，作为接口继承
13     virtual void use() const = 0;                     // 纯虚函数，作为接口继承
14 protected:
15     string name;    // 发行/出版物名称
16 };
17 Publisher::Publisher(const string &s): name {s} {
18 }
19 // 图书类: Book
20 class Book: public Publisher {
21 public:
22     Book(const string &s = "", const string &a = "");  // 构造函数
23 
24 public:
25     void publish() const override;        // 接口
26     void use() const override;            // 接口
27 
28 private:
29     string author;          // 作者
30 };
31 
32 Book::Book(const string &s, const string &a): Publisher{s}, author{a} {
33 }
34 
35 void Book::publish() const {
36     cout << "Publishing book: 《" << name << "》 by " << author << endl;
37 }
38 
39 void Book::use() const {
40     cout << "Reading book: " << name << " by " << author << endl;
41 }
42 
43 
44 // 电影类: Film
45 class Film: public Publisher {
46 public:
47     Film(const string &s = "", const string &d = "");   // 构造函数
48 
49 public:
50     void publish() const override;    // 接口
51     void use() const override;        // 接口            
52 
53 private:
54     string director;        // 导演
55 };
56 
57 Film::Film(const string &s, const string &d): Publisher{s}, director{d} {
58 }
59 
60 void Film::publish() const {
61     cout << "Publishing film: <" << name << "> directed by " << director << endl;
62 }
63 
64 void Film::use() const {
65     cout << "Watching film: " << name << " directed by " << director << endl;
66 }
67 
68 
69 // 音乐类：Music
70 class Music: public Publisher {
71 public:
72     Music(const string &s = "", const string &a = "");
73 
74 public:
75     void publish() const override;        // 接口
76     void use() const override;            // 接口
77 
78 private:
79     string artist;      // 音乐艺术家名称
80 };
81 
82 Music::Music(const string &s, const string &a): Publisher{s}, artist{a} {
83 }
84 
85 void Music::publish() const {
86     cout << "Publishing music <" << name << "> by " << artist << endl;
87 }
88 
89 void Music::use() const {
90     cout << "Listening to music: " << name << " by " << artist << endl;
91 }
View Code
 1 #include "publisher.hpp"
 2 #include <vector>
 3 #include <typeinfo>
 4 
 5 using std::vector;
 6 
 7 void test() {
 8    vector<Publisher *> v;
 9 
10    v.push_back(new Book("Harry Potter", "J.K. Rowling"));
11    v.push_back(new Film("The Godfather", "Francis Ford Coppola"));
12    v.push_back(new Music("Blowing in the wind", "Bob Dylan"));
13 
14    for(auto &ptr: v) {
15         cout << "pointer type: " << typeid(ptr).name() << endl;  // 输出指针类型
16         cout << "RTTI type: " << typeid(*ptr).name() << endl;    // 输出指针指向的对象类型
17         ptr->publish();
18         ptr->use();
19         cout << endl;
20    }
21 }
22 
23 int main() {
24     test();
25 }
View Code

截图：

task2：

代码：

 1 #pragma once
 2 
 3 #include <string>
 4 #include <iostream>
 5 #include <iomanip>
 6 
 7 using std::string;
 8 using std::ostream;
 9 using std::endl;
10 using std::setw;
11 using std::left;
12 
13 class Book {
14 public:
15     Book(const string &name, const string &author, const string &translator, const string &isbn, float price);
16 
17     friend ostream& operator<<(ostream &out, const Book &book);
18 
19 private:
20     string name;        // 书名
21     string author;      // 作者
22     string translator;  // 译者
23     string isbn;        // isbn号
24     float price;        // 定价
25 };
26 
27 // 成员函数实现
28 Book::Book(const string &name, const string &author, const string &translator, const string &isbn, float price) {
29     this->name = name;
30     this->author = author;
31     this->translator = translator;
32     this->isbn = isbn;
33     this->price = price;
34 }
35 
36 // 友元实现
37 ostream& operator<<(ostream &out, const Book &book) {
38     out << left;
39     out << setw(15) << "书名:" << book.name << endl
40         << setw(15) << "作者:" << book.author << endl
41         << setw(15) << "译者:" << book.translator << endl
42         << setw(15) << "ISBN:" << book.isbn << endl
43         << setw(15) << "定价:" << book.price;
44 
45     return out;
46 }
View Code
 1 #pragma once
 2 
 3 #include "book.hpp"
 4 #include <iostream>
 5 #include <string>
 6 #include <iomanip>
 7 
 8 using std::string;
 9 using std::cout;
10 using std::endl;
11 using std::setw;
12 
13 class BookSale {
14 public:
15     BookSale(const Book &b, float price, int amount);
16     int get_amount() const;
17     
18     friend ostream& operator<<(ostream &out, const BookSale &item);
19 
20 private:
21     Book rb;         
22     float sales_price;      // 售价
23     int sales_amount;       // 销售数量
24     float revenue;          // 营收
25 };
26 
27 // 成员函数实现
28 BookSale::BookSale(const Book &b, float price, int amount): rb{b}, sales_price(price), sales_amount{amount} {  
29     revenue = sales_amount * sales_price;
30 }
31 
32 int BookSale::get_amount() const {
33     return sales_amount;
34 }
35 
36 // 友元函数实现
37 ostream& operator<<(ostream &out, const BookSale &item) {
38     out << left;
39     out << item.rb << endl
40         << setw(15) << "售价:" << item.sales_price << endl
41         << setw(15) << "销售数量:" << item.sales_amount << endl
42         << setw(15) << "营收:" << item.revenue;
43 
44     return out;
45 }
View Code
 1 #include "booksale.hpp"
 2 #include <iostream>
 3 #include <string>
 4 #include <vector>
 5 #include <algorithm>
 6 
 7 // 按图书销售数额比较
 8 bool compare_by_amount(const BookSale &x1, const BookSale &x2) {
 9     return x1.get_amount() > x2.get_amount();
10 }
11 
12 void test() {
13     using namespace std;
14 
15      vector<BookSale> sales_lst;         // 存放图书销售记录
16 
17      int books_number;
18     cout << "录入图书数量: ";
19     cin >> books_number;
20 
21     cout << "录入图书销售记录" << endl;
22     for(int i = 0; i < books_number; ++i) {
23         string name, author, translator, isbn;
24         float price;
25         cout << string(20, '-') << "第" << i+1 << "本图书信息录入" << string(20, '-') << endl;
26         cout << "录入书名: "; cin >> name;
27         cout << "录入作者: "; cin >> author;
28         cout << "录入译者: "; cin >> translator;
29         cout << "录入isbn: "; cin >> isbn;
30         cout << "录入定价: "; cin >> price;
31 
32         Book book(name, author, translator, isbn, price);
33 
34         float sales_price;
35         int sales_amount;
36 
37         cout << "录入售价: "; cin >> sales_price;
38         cout << "录入销售数量: "; cin >> sales_amount;
39 
40         BookSale record(book, sales_price, sales_amount);
41         sales_lst.push_back(record);
42     }
43 
44     // 按销售册数排序
45     sort(sales_lst.begin(), sales_lst.end(), compare_by_amount);
46 
47     // 按销售册数降序输出图书销售信息
48     cout << string(20, '=') <<  "图书销售统计" << string(20, '=') << endl;
49     for(auto &t: sales_lst) {
50         cout << t << endl;
51         cout << string(40, '-') << endl;
52     }
53 }
54 
55 int main() {
56     test();
57 }
View Code

问题1：

通过友元函数&operator<<实现的

问题2：

通过函数compare-by-amount实现

问题3：

不理解

截图：

 task3：

代码：

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 using std::string;
 5 using std::cin;
 6 using std::cout;
 7 using std::endl;
 8 class MachinePets{
 9 public:
10     MachinePets(const string& s);
11     string get_nickname() const;
12     virtual string talk()=0;
13 private:
14     string nickname;
15 };
16 MachinePets::MachinePets(const string &s):nickname{s}{}
17 string MachinePets::get_nickname() const{
18     return nickname;
19 } 
20 class PetCats:public MachinePets{
21 public:
22     PetCats(const string& s);
23     string talk() override;    
24 };
25 PetCats::PetCats(const string &s):MachinePets{s}{}
26 string PetCats::talk() {
27     return string("miao,miao");
28 } 
29 class PetDogs:public MachinePets{
30 public:
31     PetDogs(const string& s);
32     string talk() override;    
33 };
34 PetDogs::PetDogs(const string &s):MachinePets{s}{}
35 string PetDogs::talk() {
36     return string("wang,wang");
37 }
View Code
 1 #include <iostream>
 2 #include <vector>
 3 #include "pets.hpp"
 4 
 5 void test() {
 6     using namespace std;
 7 
 8     vector<MachinePets *> pets;
 9 
10     pets.push_back(new PetCats("miku"));
11     pets.push_back(new PetDogs("da huang"));
12 
13     for(auto &ptr: pets)
14         cout <<ptr->get_nickname() << " says " << ptr->talk() << endl;
15 }
16 
17 int main() {
18     test();
19 }
View Code

截图：

task4：

代码：

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 #include<iomanip>
 5 using std::cin;
 6 using std::cout;
 7 using std::string;
 8 using std::istream;
 9 using std::ostream;
10 using std::setw;
11 using std::left;
12 class Film{
13 public:
14     Film(){}
15     friend istream& operator>>(istream& in,Film& f);
16     friend ostream& operator<<(ostream& out,const Film& f);
17     friend bool compare_by_year(const Film& f1,const Film& f2);
18     string film_name;
19     string director_name;
20     string film_area;
21     int year;
22 };
23 istream& operator>>(istream& in,Film& f){
24     cout<<"录入片名：";
25     in>>f.film_name;
26     cout<<"录入导演：";
27     in>>f.director_name;
28     cout<<"录入制片国家/地区：";
29     in>>f.film_area;
30     cout<<"录入上映年份：";
31     in>>f.year;
32     return in;
33 }
34 ostream& operator<<(ostream&out,Film& f){
35     out<<left;
36     out<<setw(20)<<f.film_name<<setw(20)<<f.director_name<<setw(20)<<f.film_area<<setw(20)<<f.year;
37     return out;
38 }
39 bool compare_by_year(const Film& f1,const Film& f2){
40     return f1.year<f2.year;
41 }
View Code
 1 #pragma once
 2 #include"film.hpp"
 3 #include <iostream>
 4 #include <string>
 5 #include <vector>
 6 #include <algorithm>
 7 
 8 void test() {
 9     using namespace std;
10     
11     int n;
12     cout << "输入电影数目: ";
13     cin >> n;
14 
15     cout << "录入" << n << "部影片信息" << endl;
16     vector<Film> film_lst;
17     for(int i = 0; i < n; ++i) {
18         Film f;
19         cout << string(20, '-') << "第" << i+1 << "部影片录入" << string(20, '-') << endl;
20         cin >> f;
21         film_lst.push_back(f);
22     }
23 
24     // 按发行年份升序排序
25     sort(film_lst.begin(), film_lst.end(), compare_by_year);
26 
27     cout << string(20, '=') + "电影信息(按发行年份)" +  string(20, '=')<< endl;
28     for(auto &f: film_lst)
29         cout << f << endl;
30 }
31 
32 int main() {
33     test();
34 }
View Code

截图：

task5：

代码：

 1 #ifndef COMPLEX_HPP  
 2 #define COMPLEX_HPP   
 3 #include <iostream>   
 4 using std::istream;
 5 using std::ostream; 
 6 template <typename T>  
 7 class Complex {  
 8 private:  
 9     T real;  
10     T imag;  
11 public:  
12     // 默认  
13     Complex(T r = 0, T i = 0) : real(r), imag(i) {}  
14     // 复制  
15     Complex(const Complex<T>& other) : real(other.real), imag(other.imag) {}  
16     // +重载 
17     Complex<T> operator+(const Complex<T>& other) const {  
18         return Complex<T>(real + other.real, imag + other.imag);  
19     }  
20     // +=重载 
21     Complex<T>& operator+=(const Complex<T>& other) {  
22         real += other.real;  
23         imag += other.imag;  
24         return *this;  
25     }  
26     // ==重载 
27     bool operator==(const Complex<T>& other) const {  
28         return real == other.real && imag == other.imag;  
29     }  
30     // 得到实部  
31     T get_real() const {  
32         return real;  
33     }  
34     // 得到虚部  
35     T get_imag() const {  
36         return imag;  
37     }  
38     // 输出重载  
39     friend ostream& operator<<(ostream& out, const Complex<T>& c) {  
40         out << c.real;  
41         if (c.imag >= 0) {  
42             out<< " + " << c.imag << "i";  
43         } else {  
44             out << " - " << -c.imag << "i";  
45         }  
46         return out;  
47     }  
48     // 输入重载  
49     friend istream& operator>>(istream& in, Complex<T>& c) {  
50         in >> c.real >>c.imag; 
51         return in;  
52     }  
53 };  
54 #endif
View Code
 1 #include "Complex.hpp"
 2 #include <iostream>
 3 
 4 using std::cin;
 5 using std::cout;
 6 using std::endl;
 7 using std::boolalpha;
 8 
 9 void test1() {
10     Complex<int> c1(2, -5), c2(c1);
11 
12     cout << "c1 = " << c1 << endl;
13     cout << "c2 = " << c2 << endl;
14     cout << "c1 + c2 = " << c1 + c2 << endl;
15     
16     c1 += c2;
17     cout << "c1 = " << c1 << endl;
18     cout << boolalpha << (c1 == c2) << endl;
19 }
20 
21 void test2() {
22     Complex<double> c1, c2;
23     cout << "Enter c1 and c2: ";
24     cin >> c1 >> c2;
25     cout << "c1 = " << c1 << endl;
26     cout << "c2 = " << c2 << endl;
27 
28     cout << "c1.real = " << c1.get_real() << endl;
29     cout << "c1.imag = " << c1.get_imag() << endl;
30 }
31 
32 int main() {
33     cout << "自定义类模板Complex测试1: " << endl;
34     test1();
35 
36     cout << endl;
37 
38     cout << "自定义类模板Complex测试2: " << endl;
39     test2();
40 }
View Code

截图：

 task6：

代码：

 1 date.h
 2 #ifndef__DATE_H__
 3 #define__DATE_H__
 4 class Date{
 5     private:
 6         int year;
 7         int month;
 8         int day;
 9         int totalDays;
10     public:
11         Date(int year,int month,int day);
12         int getYear()const {return year;}
13         int getMonth()const{return month;}
14         int getDay()const{return day;}
15         int getMaxDay()const;
16         bool isLeapYear() const{
17             return year%4==0&&year%100!=0||year%400==0;
18         }
19         void show() const;
20         int operator-(const Date& date) const{return totalDays-date.totalDays ;}
21 };
22 #endif//__DATE_H__
View Code
 1 date.cpp
 2 #include"date.h"
 3 #include<iostream>
 4 #include<cstdlib>
 5 using namespace std;
 6 namespace{
 7     const int DAYS_BEFORE_MONTH[]={0,31,59,90,120,151,181,212,243,273,304,334,365};
 8 }
 9 Date::Date(int year,int month,int day):year(year),month(month),day(day){
10     if(day<=0||day>getMaxDay()){
11         cout<<"Invalid date:";
12         show();
13         cout<<endl;
14         exit(1);
15     }
16     int years=year-1;
17     totalDays=years*365+years/4-years/100+years/400+DAYS_BEFORE_MONTH[month-1]+day;
18     if(isLeapYear()&&month>2) totalDays++;
19 } 
20 int Date::getMaxDay() const{
21     if(isLeapYear()&&month==2)    return 29;
22     else return DAYS_BEFORE_MONTH[month]-DAYS_BEFORE_MONTH[month-1];
23 }
24 void Date::show() const{
25     cout<<getYear()<<"-"<<getMonth()<<"-"<<getDay();
26 }
View Code
 1 account.h
 2 #ifndef__ACCOUNT_H__
 3 #define__ACCOUNT_H__
 4 #include"date.h"
 5 #include"accumulator.h"
 6 #include<string>
 7 class Account{
 8     private:
 9         std::string id;
10         double balance;
11         static double total;
12     protected:
13         Account(const Date &date,const std::string &id);
14         void record(const Date &date,double amount,const std::string &desc);
15         void error(const std::string &msg) const;
16     public:
17         const std::string &getId() const{return id;}
18         double getBalance() const {return balance;}
19         static double getTotal(){
20             return total; 
21         }
22         virtual void deposit(const Date& date,double amount,const std::string &desc)=0;
23         virtual void withdraw(const Date& date,double amount,const std::string &desc)=0;
24         virtual void settle(const Date &date)=0;
25         virtual void show() const;
26 };
27 #endif//__ACCOUNT_H__
View Code
 1 account.cpp
 2 #include"account.h"
 3 #include<cmath>
 4 #include<iostream>
 5 using namespace std;
 6 double Account::total = 0;
 7 Account::Account(const Date& date, const string& id) :id{ id }, balance{ 0 } {
 8     date.show(); cout << "\t#" << id << "created" << endl;
 9 }
10 void Account::record(const Date& date, double amount, const string& desc) {
11     amount = floor(amount * 100 + 0.5) / 100;
12     balance += amount;
13     total += amount;
14     date.show();
15     cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
16 }
17 void Account::show()const { cout << id << "\tBalance:" << balance; }
18 void Account::error(const string& msg)const {
19     cout << "Error(#" << id << "):" << msg << endl;
20 }
21 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :Account(date, id), rate(rate), acc(date, 0) {}
22 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
23     record(date, amount, desc);
24     acc.change(date, getBalance());
25 }
26 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
27     if (amount > getBalance()) {
28         error("not enough money");
29     }
30     else {
31         record(date, -amount, desc);
32         acc.change(date, getBalance());
33     }
34 }
35 void SavingsAccount::settle(const Date& date) {
36     double interest = acc.getSum(date) * rate / (date-Date(date.getYear() - 1, 1, 1));
37     if (interest != 0)record(date, interest, "interest");
38     acc.reset(date, getBalance());
39 }
40 CreditAccount::CreditAccount(const Date& date, const string& id, double credit, double rate, double fee) :Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) {}
41 void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
42     record(date, amount, desc);
43     acc.change(date, getDebt());
44 }
45 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
46     if (amount - getBalance() > credit) {
47         error("not enough credit");
48     }
49     else {
50         record(date, -amount, desc);
51         acc.change(date, getDebt());
52     }
53 }
54 void CreditAccount::settle(const Date& date) {
55     double interest = acc.getSum(date) * rate;
56     if (interest != 0)record(date, interest, "interest");
57     if (date.getMonth() == 1)
58         record(date, -fee, "annual fee");
59     acc.reset(date, getDebt());
60 }
61 void CreditAccount::show()const {
62     Account::show();
63     cout << "\tAvailable credit:" << getAvailableCredit();
64 }
View Code
 1 accumulator.h
 2 #ifndef__ACCUMULATOR_H__
 3 #define__ACCUMULATOR_H__
 4 #include"date.h"
 5 class Accumulator{
 6     private:
 7         Date lastDate;
 8         double value;
 9         double sum;
10     public:
11         double getSum(const Date &date) const{return sum+value*(date-lastDate);}
12 };
13 #endif//__ACCUMULATOR_H__
View Code
 1 task5.6.cpp
 2 #include"account.h""
 3 #include<iostream>
 4 using namespace std;
 5 int main()
 6 {
 7     Date date(2008,11,1);
 8     SavingsAccount sa1(date,"s3755271",0.015);
 9     SavingsAccount sa2(date,"02342342",0.015);
10     CreditAccount ca(date,"C5392394",10000,0.0005,50);
11     Account *accounts[]={&sa1,&sa2,&ca};
12     const int n=sizeof(accounts)/sizeof(Account *);
13     cout<<"(d)deposit (w)withdraw (s) show (c) change day (n) next month (e) exit"<<endl;
14     char cmd;
15     do{
16         date.show();
17         cout<<"\tTotal:"<<Account::getTotal()<<"\tcommand>";
18         int index,day;
19         double amount;
20         string desc;
21         cin>>cmd;
22         switch(cmd){
23             case 'd':
24                 cin>>index>>amount;
25                 getline(cin,desc);
26                 accounts[index]->deposit(date,amount,desc);
27                 break;
28             case 'w':
29                cin>>index>>amount;
30                getline(cin,desc);
31                accounts[index]->withdraw(date,amount,desc);
32                break;
33             case 's':
34                 for(int i=0;i<n;i++)
35                 {
36                     cout<<"["<<i<<"]";
37                     accounts[i]->show();
38                     cout<<endl;
39                 }
40                 break;
41             case 'c':
42                 cin>>day;
43                 if(day<date.getDay())
44                     cout<<"You cannot specify a previous day";
45                 else if(day>date.getDay())
46                     cout<<"Invalid day";
47                 else
48                     date=Date(date.getYear(),date.getMonth(),day);
49                 break;
50             case 'n':
51                 if(date.getMonth()==12)
52                     date=Date(date.getYear()+1,1,1);
53                 else
54                     date=Date(date.getYear(),date.getMonth()+1,1);
55                 for(int i=0;i<n;i++)
56                 {
57                     accounts[i]->settle(date);        
58                 }
59                 break;    
60        }
61     }while(cmd!='e');
62     return 0;
63 }
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posted on 2024-12-06 22:26  nofear妈  阅读(5)  评论(0)  编辑  收藏  举报

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