实验五 继承和多态

实验任务1：

（1）代码部分：

#pragma once

#include <iostream>
#include <string>

using std::cout;
using std::endl;
using std::string;

// 发行/出版物类：Publisher （抽象类）
class Publisher {
public:
    Publisher(const string &s = "");            // 构造函数

public:
    virtual void publish() const = 0;                 // 纯虚函数，作为接口继承
    virtual void use() const = 0;                     // 纯虚函数，作为接口继承

protected:
    string name;    // 发行/出版物名称
};

Publisher::Publisher(const string &s): name {s} {
}


// 图书类: Book
class Book: public Publisher {
public:
    Book(const string &s = "", const string &a = "");  // 构造函数

public:
    void publish() const override;        // 接口
    void use() const override;            // 接口

private:
    string author;          // 作者
};

Book::Book(const string &s, const string &a): Publisher{s}, author{a} {
}

void Book::publish() const {
    cout << "Publishing book: 《" << name << "》 by " << author << endl;
}

void Book::use() const {
    cout << "Reading book: " << name << " by " << author << endl;
}


// 电影类: Film
class Film: public Publisher {
public:
    Film(const string &s = "", const string &d = "");   // 构造函数

public:
    void publish() const override;    // 接口
    void use() const override;        // 接口            

private:
    string director;        // 导演
};

Film::Film(const string &s, const string &d): Publisher{s}, director{d} {
}

void Film::publish() const {
    cout << "Publishing film: <" << name << "> directed by " << director << endl;
}

void Film::use() const {
    cout << "Watching film: " << name << " directed by " << director << endl;
}


// 音乐类：Music
class Music: public Publisher {
public:
    Music(const string &s = "", const string &a = "");

public:
    void publish() const override;        // 接口
    void use() const override;            // 接口

private:
    string artist;      // 音乐艺术家名称
};

Music::Music(const string &s, const string &a): Publisher{s}, artist{a} {
}

void Music::publish() const {
    cout << "Publishing music <" << name << "> by " << artist << endl;
}

void Music::use() const {
    cout << "Listening to music: " << name << " by " << artist << endl;
}
#include "publisher.hpp"
#include <vector>
#include <typeinfo>

using std::vector;

void test() {
   vector<Publisher *> v;

   v.push_back(new Book("Harry Potter", "J.K. Rowling"));
   v.push_back(new Film("The Godfather", "Francis Ford Coppola"));
   v.push_back(new Music("Blowing in the wind", "Bob Dylan"));

   for(auto &ptr: v) {
        cout << "pointer type: " << typeid(ptr).name() << endl;  // 输出指针类型
        cout << "RTTI type: " << typeid(*ptr).name() << endl;    // 输出指针指向的对象类型
        ptr->publish();
        ptr->use();
        cout << endl;
   }
}

int main() {
    test();
}

 

（2）运行结果：

 

 

 

实验任务2：

（1）代码部分：

#pragma once

#include <string>
#include <iostream>
#include <iomanip>

using std::string;
using std::ostream;
using std::endl;
using std::setw;
using std::left;

class Book {
public:
    Book(const string &name, const string &author, const string &translator, const string &isbn, float price);

    friend ostream& operator<<(ostream &out, const Book &book);

private:
    string name;        // 书名
    string author;      // 作者
    string translator;  // 译者
    string isbn;        // isbn号
    float price;        // 定价
};

// 成员函数实现
Book::Book(const string &name, const string &author, const string &translator, const string &isbn, float price) {
    this->name = name;
    this->author = author;
    this->translator = translator;
    this->isbn = isbn;
    this->price = price;
}

// 友元实现
ostream& operator<<(ostream &out, const Book &book) {
    out << left;
    out << setw(15) << "书名:" << book.name << endl
        << setw(15) << "作者:" << book.author << endl
        << setw(15) << "译者:" << book.translator << endl
        << setw(15) << "ISBN:" << book.isbn << endl
        << setw(15) << "定价:" << book.price;

    return out;
}
#pragma once

#include "book.hpp"
#include <iostream>
#include <string>
#include <iomanip>

using std::string;
using std::cout;
using std::endl;
using std::setw;

class BookSale {
public:
    BookSale(const Book &b, float price, int amount);
    int get_amount() const;
    
    friend ostream& operator<<(ostream &out, const BookSale &item);

private:
    Book rb;         
    float sales_price;      // 售价
    int sales_amount;       // 销售数量
    float revenue;          // 营收
};

// 成员函数实现
BookSale::BookSale(const Book &b, float price, int amount): rb{b}, sales_price(price), sales_amount{amount} {  
    revenue = sales_amount * sales_price;
}

int BookSale::get_amount() const {
    return sales_amount;
}

// 友元函数实现
ostream& operator<<(ostream &out, const BookSale &item) {
    out << left;
    out << item.rb << endl
        << setw(15) << "售价:" << item.sales_price << endl
        << setw(15) << "销售数量:" << item.sales_amount << endl
        << setw(15) << "营收:" << item.revenue;

    return out;
}
#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();
}

 

（2）运行结果：

 

 

 

 

实验任务3：

（1）代码部分：

#pragma once
#include<iostream>
using namespace std;
class MachinePets {
private:
    string nickname;
public:
    MachinePets(const string &s);
    virtual string talk() const = 0;
    string get_nickname() const;
};
MachinePets::MachinePets(const string& s) :nickname{ s }{}
string MachinePets::get_nickname()const {
    return nickname;
}
class PetCats :public MachinePets {
public:
    PetCats(const string& s);
    string talk()const override;
};
PetCats::PetCats(const string& s) :MachinePets{ s } {
}
string PetCats::talk()const {
    return "miao wu~";
}
class PetDogs :public MachinePets {
public:
    PetDogs(const string& s);
    string talk()const override;
};
PetDogs::PetDogs(const string &s):MachinePets{s}{}
string PetDogs::talk()const {
    return "wang wang ~";
}
#include <iostream>
#include <vector>
#include "pets.hpp"

void test() {
    using namespace std;

    vector<MachinePets *> pets;

    pets.push_back(new PetCats("miku"));
    pets.push_back(new PetDogs("da huang"));

    for(auto &ptr: pets)
        cout <<ptr->get_nickname() << " says " << ptr->talk() << endl;
}

int main() {
    test();
}

 

（2）运行结果：

 

 

 

实验任务4：

（1）代码部分：

film.hpp
#pragma once
 #include<iostream>
 #include<iomanip>
 using namespace std;

 using std::left;

 class film {
 private:
         string name, director, area, time;
 public:
         film(const string & name = "", const string & director = "", const string & area = "", const string & time = "");
         friend ostream & operator<<(ostream & out, const film & f);
         friend istream & operator>>(istream & in, film & f);
         string get_year()const;
    
};
 film::film(const string & name, const string & director, const string & area, const string & time) {
         this->name = name;
         this->director = director;
         this->area = area;
         this->time = time;
    
}
 string film::get_year()const {
         return time;
    
}
 ostream & operator<<(ostream & out, const film & f) {
         out << left;
         out << setw(10)<<f.name << setw(15) << f.director << setw(10) << f.area << setw(10) << f.time << endl;
         return out;
    
}
 istream & operator>>(istream & in, film & f) {
        std::cout << "录入片名：";in >> f.name;
        std::cout << "录入导演：";in >> f.director;
        std::cout << "录入制片国家/地区：";in >> f.area;
        std::cout << "录入上映年份：";in >> f.time;
         return in;
    
}
 bool compare_by_year(const film & f1, const film & f2) {
         return f1.get_year() < f2.get_year();
    
}
task4.cpp
#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();
}

 

（2）运行结果：

 

 

 

 

 

实验任务5：

（1）代码部分：

Complex.hpp
#pragma once
#include<iostream>
using namespace std;

template <typename T>
class Complex {
public:
    Complex(const T& r = 0, const T& i = 0) : real{ r }, imag{ i } {}
    T get_real()const {
        return real;
    }
    T get_imag()const {
        return imag;
    }
    Complex operator+=(const Complex c) {
        real += c.real;
        imag += c.imag;
        return *this;
    }
    friend Complex operator+(const Complex& c1, const Complex& c2) {
        return Complex<T>(c1.real + c2.real, c1.imag + c2.imag);
    }

    friend bool operator==(const Complex& c1, const Complex& c2) {
        return c1.real == c2.real && c1.imag == c2.imag;
    }

    friend istream& operator>>(istream& in,  Complex& c) {
        in >> c.real >> c.imag;
        return in;
    }

    friend ostream& operator<<(ostream& out,const Complex& c) {
        if (c.imag > 0)
            out << c.real << '+' << c.imag << 'i';
        else
            out << c.real << '-' << -c.imag << 'i';
        return out;
    }


private:
    T real;
    T imag;
};
task5
#include "Complex.hpp"
#include <iostream>

using std::cin;
using std::cout;
using std::endl;
using std::boolalpha;

void test1() {
    Complex<int> c1(2, -5), c2(c1);

    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c1 + c2 = " << c1 + c2 << endl;

    c1 += c2;
    cout << "c1 = " << c1 << endl;
    cout << boolalpha << (c1 == c2) << endl;
}

void test2() {
    Complex<double> c1, c2;
    cout << "Enter c1 and c2: ";
    cin >> c1 >> c2;
    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;

    cout << "c1.real = " << c1.get_real() << endl;
    cout << "c1.imag = " << c1.get_imag() << endl;
}

int main() {
    cout << "自定义类模板Complex测试1: " << endl;
    test1();

    cout << endl;

    cout << "自定义类模板Complex测试2: " << endl;
    test2();
}

 

（2）运行结果：

 

 

实验任务6：

（1）代码部分：

#pragma once
#include"date.h"
#include"accumulator.h"
#include<string>
using namespace std;
class Account {
private:
        string id;
        double balance;
        static double total;
protected:
        Account(const Date & date, const string & id);
        void record(const Date & date, double amount, const string & desc);
        void error(const string & msg) const;
public:const string & getId() { return id; }
               double getBalance()const { return balance; }
               static double getTotal() { return total; }
               virtual void deposit(const Date & date, double amount, const string & desc) = 0;
               virtual void withdraw(const Date & date, double amount, const string & desc) = 0;
               virtual void settle(const Date & date) = 0;
               virtual void show()const;
};
class SavingsAccount :public Account {
private:
        Accumulator acc;
        double rate;
public:
        SavingsAccount(const Date & date, const string & id, double rate);
        double getRate() const { return  rate; }
        void deposit(const Date & date, double amount, const string & desc);
        void withdraw(const Date & date, double amount, const string & desc);
        void settle(const Date & date);
};
class CreditAccount :public Account {
private:
        Accumulator acc;
        double credit;
        double rate;
        double fee;
        double getDebt()const {
                double balance = getBalance();
                return(balance < 0 ? balance : 0);
    }
public:CreditAccount(const Date & date, const string & id, double credit, double rate, double fee);
                double getCredit()const { return credit; }
                double getRate()const { return rate; }
                double getFee() const { return fee; }
                double getAvailableCredit()const {
                        if (getBalance() < 0)return credit + getBalance();
                        else return credit;
          }
                void deposit(const Date & date, double amount, const string & desc);
                void withdraw(const Date & date, double amount, const string & desc);
                void settle(const Date & date);
                void show()const;
};
#pragma once
#include "date.h"
class Accumulator {
private:
        Date lastDate;
        double value;
        double sum;
public:
        Accumulator(const Date & date, double value) :lastDate(date), value(value), sum{ 0 } {}
        double getSum(const Date & date) const {
                return sum + value * (date - lastDate);
    }
        void change(const Date & date, double value) {
                sum = getSum(date);
                lastDate = date;
                this->value = value;
    }
        void reset(const Date & date, double value) {
                lastDate = date;
                this->value;
                sum = 0;
    }
};
#pragma once
class Date {
private:
    int year;
    int month;
    int day;
    int totalDays;
public:
    Date(int year, int month, int day);
    int getYear()const { return year; }
    int getMonth()const { return month; }
    int getDay()const { return day; }
    int getMaxDay()const;
    bool isLeapYear()const {
        return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    }
    void show()const;
    int operator - (const Date & date)const {
        return totalDays - date.totalDays;
    }
};
#include "account.h"
#include <cmath>
#include<iostream>
using namespace std;
double Account::total = 0;
Account::Account(const Date & date, const string & id) :id(id), balance(0) {
        date.show();
        cout << "\t#" << id << "created" << endl;
}
void Account::record(const Date & date, double amount, const string & desc) {
        amount = floor(amount * 100 + 0.5) / 100;
        balance += amount;
        total += amount;
        date.show();
        cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
}
void Account::show()const { cout << id << "\tBalance:" << balance; }
void Account::error(const string & msg)const {
        cout << "Error(#" << id << "):" << msg << endl;
}
SavingsAccount::SavingsAccount(const Date & date, const string & id, double rate) :Account(date, id), rate(rate), acc(date, 0) {}
void SavingsAccount::deposit(const Date & date, double amount, const string & desc) {
        record(date, amount, desc);
        acc.change(date, getBalance());
}
void SavingsAccount::withdraw(const Date & date, double amount, const string & desc) {
        if (amount > getBalance()) {
                error("not enough money");
    }
        else {
                record(date, -amount, desc);
                acc.change(date, getBalance());
    }
}
void SavingsAccount::settle(const Date & date) {
        if (date.getMonth() == 1) {
                double interest = acc.getSum(date) * rate / (date - Date(date.getYear() - 1, 1, 1));
                if (interest != 0) record(date, interest, "interest");
                acc.reset(date, getBalance());
    }
}
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) {}
void CreditAccount::deposit(const Date & date, double amount, const string & desc) {
        record(date, amount, desc);
        acc.change(date, getDebt());
}
void CreditAccount::withdraw(const Date & date, double amount, const string & desc) {
        if (amount - getBalance() > credit) {
                error("not enouogh credit");
    }
        else {
                record(date, -amount, desc);
                acc.change(date, getDebt());
    }
}
void CreditAccount::settle(const Date & date) {
        double interest = acc.getSum(date) * rate;
        if (interest != 0) record(date, interest, "interest");
        if (date.getMonth() == 1)record(date, -fee, "annual fee");
        acc.reset(date, getDebt());
}
void CreditAccount::show()const {
        Account::show();
        cout << "\tAvailable credit:" << getAvailableCredit();
}
#include"account.h"
#include<iostream>
using namespace std;
int main() {
        Date date(2008, 11, 1);
        SavingsAccount sa1(date, "S3755217", 0.015);
        SavingsAccount sa2(date, "02342342", 0.015);
        CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
        Account * accounts[] = { &sa1,&sa2,&ca };
        const int n = sizeof(accounts) / sizeof(Account*);
        cout << "(d)deposit (w)withdraw (s)show (c)change day (n)next month (e)exit" << endl;
        char cmd;
        do {
                date.show();
                cout << "\tTotal:" << Account::getTotal() << "\tcommand>";
                int index, day;
                double amount;
                string desc;
                cin >> cmd;
                switch (cmd) {
                case 'd':
                        cin >> index >> amount;
                        getline(cin, desc);
                        accounts[index]->deposit(date, amount, desc);
                        break;
                case 'w':
                        cin >> index >> amount;
                        getline(cin, desc);
                        accounts[index]->withdraw(date, amount, desc);
                        break;
                case 's':
                        for (int i = 0; i < n; i++) {
                                cout << "[" << i << "]";
                                accounts[i]->show();
                                cout << endl;
            }
                        break;
                case 'c':
                        cin >> day;
                        if (day < date.getDay()) {
                                cout << "You cannot specify a previous day";
            }
                        else if (day > date.getMaxDay())
                                cout << "Invalid day";
                        else date = Date(date.getYear(), date.getMonth(), day);
                        break;
                case 'n':
                        if (date.getMonth() == 12)
                                date = Date(date.getYear() + 1, 1, 1);
                        else date = Date(date.getYear(), date.getMonth() + 1, 1);
                        for (int i = 0; i < n; i++) {
                                accounts[i]->settle(date);
            }
                        break;
        }
    } while (cmd != 'e');
        return 0;
}
#include"date.h"
#include<iostream>
#include<cstdlib>
using namespace std;
namespace {
    const int DAYS_BEFIRE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 };
}
Date::Date(int year, int month, int day) :year(year), month(month), day(day) {
    if (day <= 0 || day > getMaxDay()) {
        cout << "Invalid date:";
        show();
        cout << endl;
        exit(1);
    }
    int years = year - 1;
    totalDays = years * 365 + year / 4 - years / 100 + years / 400 + DAYS_BEFIRE_MONTH[month - 1] + day;
    if (isLeapYear() && month > 2)totalDays++;
}
int Date::getMaxDay()const {
        if (isLeapYear() && month == 2)
                return 29;
        else return DAYS_BEFIRE_MONTH[month] - DAYS_BEFIRE_MONTH[month - 1];
}
void Date::show()const {
    cout << getYear() << "-" << getMonth() << "-" << getDay();
}