实验5 继承和多态

实验任务1：

 1 #pragma once
 2 
 3 #include <iostream>
 4 #include <string>
 5 
 6 using std::cout;
 7 using std::endl;
 8 using std::string;
 9 
10 // 发行/出版物类：Publisher （抽象类）
11 class Publisher {
12 public:
13     Publisher(const string &s = "");            // 构造函数
14 
15 public:
16     virtual void publish() const = 0;                 // 纯虚函数，作为接口继承
17     virtual void use() const = 0;                     // 纯虚函数，作为接口继承
18 
19 protected:
20     string name;    // 发行/出版物名称
21 };
22 
23 Publisher::Publisher(const string &s): name {s} {
24 }
25 
26 
27 // 图书类: Book
28 class Book: public Publisher {
29 public:
30     Book(const string &s = "", const string &a = "");  // 构造函数
31 
32 public:
33     void publish() const override;        // 接口
34     void use() const override;            // 接口
35 
36 private:
37     string author;          // 作者
38 };
39 
40 Book::Book(const string &s, const string &a): Publisher{s}, author{a} {
41 }
42 
43 void Book::publish() const {
44     cout << "Publishing book: 《" << name << "》 by " << author << endl;
45 }
46 
47 void Book::use() const {
48     cout << "Reading book: " << name << " by " << author << endl;
49 }
50 
51 
52 // 电影类: Film
53 class Film: public Publisher {
54 public:
55     Film(const string &s = "", const string &d = "");   // 构造函数
56 
57 public:
58     void publish() const override;    // 接口
59     void use() const override;        // 接口
60 
61 private:
62     string director;        // 导演
63 };
64 
65 Film::Film(const string &s, const string &d): Publisher{s}, director{d} {
66 }
67 
68 void Film::publish() const {
69     cout << "Publishing film: <" << name << "> directed by " << director << endl;
70 }
71 
72 void Film::use() const {
73     cout << "Watching film: " << name << " directed by " << director << endl;
74 }
75 
76 
77 // 音乐类：Music
78 class Music: public Publisher {
79 public:
80     Music(const string &s = "", const string &a = "");
81 
82 public:
83     void publish() const override;        // 接口
84     void use() const override;            // 接口
85 
86 private:
87     string artist;      // 音乐艺术家名称
88 };
89 
90 Music::Music(const string &s, const string &a): Publisher{s}, artist{a} {
91 }
92 
93 void Music::publish() const {
94     cout << "Publishing music <" << name << "> by " << artist << endl;
95 }
96 
97 void Music::use() const {
98     cout << "Listening to music: " << name << " by " << artist << endl;
99 }

publisher.hpp

 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 }

task1.cpp

实验任务2：

 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 }

book.hpp

 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 }

booksale.hpp

#include "booksale.hpp"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

// 按图书销售数额比较
bool compare_by_amount(const BookSale &x1, const BookSale &x2) {
    return x1.get_amount() > x2.get_amount();
}

void test() {
    using namespace std;

     vector<BookSale> sales_lst;         // 存放图书销售记录

     int books_number;
    cout << "录入图书数量: ";
    cin >> books_number;

    cout << "录入图书销售记录" << endl;
    for(int i = 0; i < books_number; ++i) {
        string name, author, translator, isbn;
        float price;
        cout << string(20, '-') << "第" << i+1 << "本图书信息录入" << string(20, '-') << endl;
        cout << "录入书名: "; cin >> name;
        cout << "录入作者: "; cin >> author;
        cout << "录入译者: "; cin >> translator;
        cout << "录入isbn: "; cin >> isbn;
        cout << "录入定价: "; cin >> price;

        Book book(name, author, translator, isbn, price);

        float sales_price;
        int sales_amount;

        cout << "录入售价: "; cin >> sales_price;
        cout << "录入销售数量: "; cin >> sales_amount;

        BookSale record(book, sales_price, sales_amount);
        sales_lst.push_back(record);
    }

    // 按销售册数排序
    sort(sales_lst.begin(), sales_lst.end(), compare_by_amount);

    // 按销售册数降序输出图书销售信息
    cout << string(20, '=') <<  "图书销售统计" << string(20, '=') << endl;
    for(auto &t: sales_lst) {
        cout << t << endl;
        cout << string(40, '-') << endl;
    }
}

int main() {
    test();
}

task2.cpp

实验任务3：

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 using namespace std;
 5 
 6 class MachinePets
 7 {
 8 private:
 9     string nickname;
10 
11 public:
12     MachinePets(const string& name) :nickname(name) {}
13     string get_nickname()const;
14     virtual string talk() = 0;
15 
16 };
17 
18 string MachinePets::get_nickname()const
19 {
20     return nickname;
21 }
22 
23 
24 class PetCats :public MachinePets
25 {
26 public:
27     PetCats(const string& s) :MachinePets(s) {}
28     string talk()override;
29 
30 };
31 
32 string PetCats::talk()
33 {
34     return "miao wu~";
35 
36 }
37 
38 
39 class PetDogs :public MachinePets
40 {
41 public:
42     PetDogs(const string& s) :MachinePets(s) {}
43     string talk()override;
44 
45 };
46 
47 string PetDogs::talk()
48 {
49     return "wang wang~";
50 }

pets.hpp

 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 }

task.cpp

实验任务4：

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 #include<iomanip>
 5 using namespace std;
 6 
 7 class Film
 8 {
 9 private:
10     string pianming;
11     string daoyan;
12     string diqu;
13     int  nianfen;
14 
15 public:
16     friend istream& operator>>(istream& in, Film& f);
17     friend ostream& operator<<(ostream& out, const Film& f);
18     friend bool compare_by_year(const Film& f1, const Film& f2);
19 
20 };
21 
22 istream& operator>>(istream &in,Film& f)
23 {
24     cout << "录入片名:"; cin >> f.pianming;
25     cout << "录入导演:"; cin >> f.daoyan;
26     cout << "录入制片国家/地区:"; cin >> f.diqu;
27     cout << "录入上映年份:"; cin >> f.nianfen;
28     return in;
29 
30 }
31 
32 ostream& operator<<(ostream& out, const Film& f)
33 {
34     out << left;
35     out << setw(15) << f.pianming << setw(15) << f.daoyan << setw(15) << f.diqu << setw(15) << f.nianfen;
36     return out;
37 }
38 
39 
40 bool compare_by_year(const Film& f1, const Film& f2)
41 {
42     return f1.nianfen < f2.nianfen;
43 }

film.hpp

#include "film.hpp"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

void test() {
    using namespace std;

    int n;
    cout << "输入电影数目: ";
    cin >> n;

    cout << "录入" << n << "部影片信息" << endl;
    vector<Film> film_lst;
    for(int i = 0; i < n; ++i) {
        Film f;
        cout << string(20, '-') << "第" << i+1 << "部影片录入" << string(20, '-') << endl;
        cin >> f;
        film_lst.push_back(f);
    }

    // 按发行年份升序排序
    sort(film_lst.begin(), film_lst.end(), compare_by_year);

    cout << string(20, '=') + "电影信息(按发行年份)" +  string(20, '=')<< endl;
    for(auto &f: film_lst)
        cout << f << endl;
}

int main() {
    test();
}

task4.cpp

实验任务5：

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 using namespace std;
 5 
 6 template<typename T>
 7 class Complex{
 8     private:
 9         T real;
10         T imag;
11     public:
12         Complex(T r=0,T i=0):real(r),imag(i) {}
13         Complex(const Complex<T>& other):real(other.real),imag(other.imag){}
14         T get_real() const{return real;}
15         T get_imag() const{return imag;}
16         Complex<T> &operator+=(const Complex<T>& other){
17             real+=other.real;
18             imag+=other.imag;
19             return *this;
20         }
21         Complex<T> operator+(const Complex<T>& other) const{
22             return Complex<T>(real+other.real,imag+other.imag);
23         }
24         bool operator==(const Complex<T>&other) const{
25             return real==other.real&&imag==other.imag;
26         }
27         friend istream& operator>>(istream &is,Complex<T>& c){
28             is>>c.real>>c.imag;
29             return is;
30         }
31         friend ostream& operator<<(ostream& os, const Complex<T>& c){
32             if(c.imag>=0){
33                 os<<c.real<<"+"<<c.imag<<"i";
34             }
35             else{
36                 os<<c.real<<c.imag<<"i";
37             }
38             return os;
39         }
40 };

complex.hpp

 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 }

task5.cpp

实验任务6：

 1 #pragma once
 2 
 3  class Date {
 4  private:
 5         int year;
 6         int month;
 7         int day;
 8         int totalDays;
 9 
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     }
20          void show() const;
21         int operator-(const Date & date) const {
22                 return totalDays - date.totalDays;
23 
24     }
25 
26 };

date.h

 1 #include "date.h"
 2 #include <iostream>
 3 #include <cstdlib>
 4 using namespace std;
 5 
 6 namespace {
 7     const int DAYS_BEFORE_MONTH[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
 8 
 9 }
10 
11 Date::Date(int year, int month, int day) : year(year), month(month), day(day) {
12     if (day <= 0 || day > getMaxDay()) {
13         cout << "Invalid date: ";
14         show();
15         cout << endl;
16         exit(1);
17 
18     }
19     int years = year - 1;
20     totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
21     if (isLeapYear() && month > 2) totalDays++;
22 
23 }
24 
25 int Date::getMaxDay() const {
26     if (isLeapYear() && month == 2)
27         return 29;
28     else return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
29 
30 }
31 
32 void Date::show() const {
33     cout << getYear() << "-" << getMonth() << "-" << getDay();
34 
35 }

date.cpp

 1 #pragma once
 2 #include "date.h"
 3 
 4 class Accumulator {
 5 private:
 6     Date lastDate;
 7     double value;
 8     double sum;
 9 
10 public:
11 
12     double getSum(const Date& date) const {
13         return sum + value * (date - lastDate);
14 
15     }
16     Accumulator(const Date& date, double value) : lastDate(date), value(value), sum{ 0 } {}
17 
18     void change(const Date& date, double value) {
19         sum = getSum(date);
20         lastDate = date;
21         this->value = value;
22 
23     }
24 
25     void reset(const Date& date, double value) {
26         lastDate = date;
27         this->value = value;
28         sum = 0;
29     }
30 
31 };

accumulator.h

 1 #pragma once
 2 #include "date.h"
 3 #include "accumulator.h"
 4 #include <string>
 5 using namespace std;
 6 
 7 class Account {
 8 private:
 9     string id;
10     double balance;
11     static double total;
12 protected:
13     Account(const Date& date, const string& id);
14     void record(const Date& date, double amount, const string& desc);
15     void error(const string& msg) const;
16 
17 public:
18     const string& getId() { return id; }
19     double getBalance() const { return balance; }
20     static double getTotal() { return total; }
21     virtual void deposit(const Date& date, double amount, const string& desc) = 0;
22     virtual void withdraw(const Date& date, double amount, const string& desc) = 0;
23     virtual void settle(const Date& date) = 0;
24     virtual void show() const;
25 
26 };
27 
28 class SavingsAccount : public Account {
29 private:
30     Accumulator acc;
31     double rate;
32 public:
33     SavingsAccount(const Date& date, const string& id, double rate);
34     double getRate() const { return rate; }
35     void deposit(const Date& date, double amount, const string& desc);
36     void withdraw(const Date& date, double amount, const string& desc);
37     void settle(const Date& date);
38 
39 };
40 
41 class CreditAccount : public Account {
42 private:
43     Accumulator acc;
44     double credit;
45     double rate;
46     double fee;
47     double getDebt() const {
48         double balance = getBalance();
49         return (balance < 0 ? balance : 0);
50 
51     }
52 public:
53     CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
54     double getCredit() const { return credit; }
55     double getRate() const { return rate; }
56     double getFee() const { return fee; }
57     double getAvailableCredit() const {
58         if (getBalance() < 0) return credit + getBalance();
59         else return credit;
60 
61     }
62     void deposit(const Date& date, double amount, const string& desc);
63     void withdraw(const Date& date, double amount, const string& desc);
64     void settle(const Date& date);
65     void show() const;
66 
67 };

account.h

 1 #include "account.h"
 2 #include <cmath>
 3 #include<iostream>
 4 using namespace std;
 5 
 6 double Account::total = 0;
 7 Account::Account(const Date& date, const string& id) : id(id), balance(0) {
 8     date.show();
 9     cout << "\t#" << id << " created" << endl;
10 
11 }
12 
13 void Account::record(const Date& date, double amount, const string& desc) {
14     amount = floor(amount * 100 + 0.5) / 100;
15     balance += amount;
16     total += amount;
17     date.show();
18     cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
19 
20 }
21 
22 void Account::show() const {
23     cout << id << "\tBalance: " << balance;
24 
25 }
26 
27 void Account::error(const string& msg) const {
28     cout << "Error (#" << id << "): " << msg << endl;
29 
30 }
31 
32 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate)
33     : Account(date, id), rate(rate), acc(date, 0) {}
34 
35 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
36     record(date, amount, desc);
37     acc.change(date, getBalance());
38 
39 }
40 
41 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
42     if (amount > getBalance()) {
43         error("not enough money");
44 
45     }
46     else {
47         record(date, -amount, desc);
48         acc.change(date, getBalance());
49 
50     }
51 
52 }
53 
54 void SavingsAccount::settle(const Date& date) {
55     if (date.getMonth() == 1)
56     {
57         double interest = acc.getSum(date) * rate / (date - Date(date.getYear() - 1, 1, 1));
58         if (interest != 0) record(date, interest, "interest");
59         acc.reset(date, getBalance());
60     }
61 }
62 
63 CreditAccount::CreditAccount(const Date& date, const string& id, double credit, double rate, double fee)
64     : Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) {}
65 
66 void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
67     record(date, amount, desc);
68     acc.change(date, getDebt());
69 
70 }
71 
72 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
73     if (amount - getBalance() > credit) {
74         error("not enough credit");
75 
76     }
77     else {
78         record(date, -amount, desc);
79         acc.change(date, getDebt());
80 
81     }
82 
83 }
84 
85 void CreditAccount::settle(const Date& date) {
86     double interest = acc.getSum(date) * rate;
87     if (interest != 0) record(date, interest, "interest");
88     if (date.getMonth() == 1) record(date, -fee, "annual fee");
89     acc.reset(date, getDebt());
90 
91 }
92 
93 void CreditAccount::show() const {
94     Account::show();
95     cout << "\tAvailable credit: " << getAvailableCredit();
96 
97 }

account.cpp

 1 #include "account.h"
 2 #include<iostream>
 3 using namespace std;
 4 
 5 int main() {
 6     Date date(2008, 11, 1);
 7     SavingsAccount sa1(date, "S3755217", 0.015);
 8     SavingsAccount sa2(date, "02342342", 0.015);
 9     CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
10     Account* accounts[] = { &sa1, &sa2, &ca };
11     const int n = sizeof(accounts) / sizeof(Account*);
12     cout << "(d)deposit (w)withdraw (s)show (c)change day (n)next month (e)exit" << endl;
13     char cmd;
14     do {
15         date.show();
16         cout << "\tTotal:" << Account::getTotal() << "\tcommand>";
17         int index, day;
18         double amount;
19         string desc;
20         cin >> cmd;
21         switch (cmd) {
22         case 'd':
23             cin >> index >> amount;
24             getline(cin, desc);
25             accounts[index]->deposit(date, amount, desc);
26             break;
27         case 'w':
28             cin >> index >> amount;
29             getline(cin, desc);
30             accounts[index]->withdraw(date, amount, desc);
31             break;
32         case 's':
33             for (int i = 0; i < n; i++) {
34                 cout << "[" << i << "]";
35                 accounts[i]->show();
36                 cout << endl;
37 
38             }
39             break;
40         case 'c':
41             cin >> day;
42             if (day < date.getDay()) {
43                 cout << "You cannot specify a previous day";
44 
45             }
46             else if (day > date.getMaxDay())
47                 cout << "Invalid day";
48             else 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             {
55                 date = Date(date.getYear(), date.getMonth() + 1, 1);
56             }
57             for (int i = 0; i < n; i++) {
58                 accounts[i]->settle(date);
59 
60             }
61             break;
62 
63         }
64 
65     } while (cmd != 'e');
66     return 0;
67 
68 }

task6.cpp

好处：Account 中将账户的公共操作都声明为虚函数，可以通过基类的指针来执行各种操作，使得各种类型的账户对象都可以通过一个基类指针数组来访问，从而可以通过一个统一的方式来操作各个账户。

不足：没有用户交互界面，内容直接被创建，有一定局限性

posted @ 2024-12-06 16:49 nightlight 阅读(7) 评论(0) 编辑收藏举报

刷新页面返回顶部

实验5 继承和多态

公告