实验五 继承和多态

实验一：

代码：

publisher.hpp:

#pragma once

#include<iostream>
#include<string>

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

class Publisher {
public:
    Publisher(const string& s = "");

public:
    virtual void publish()const = 0;
    virtual void use()const = 0;

protected:
    string name;
};

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

class Book :public Publisher {
public:
    Book(const string& s = "", const string& a = "");

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

private:
    string author;
};

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;
}

class Film :public Publisher {
public:
    Film(const string& s = "", const string& d = "");

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

private:
    string director;
};

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;
}

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

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

private:
    string artist;
};

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;
}

task1.cpp:

#include"publisher.hpp"
#include<vector>
#include<typeinfo>

using std::vector;

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

    v.push_back(new Book("Harry Ptter", "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;

        cout << "RTTI type:" << typeid(*ptr).name() << endl;

        ptr->publish();
        ptr->use();
        cout << endl;
    }
}

int main() {
    test();
}

运行结果：

实验二：

代码：

book.hpp:

#pragma once

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


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


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

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

private:
    string name;
    string author;
    string translator;
    string isbn;
    float price;
};

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;
}

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) << "定价：" << book.price;

    return out;
}

booksale.hpp:

#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;
    int sales_amount;
    float revenue;
};

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;
}

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;
}

task2.cpp:

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

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;

    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);
    }

    sort(sales_lst.begin(), sales_lst.end(), compare_by_amount);

    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();
}

运行结果：

实验三：

代码：

pets.hpp:

#pragma once
#include<iostream>
#include<string>

using namespace std;

class MachinePets {
public:
    MachinePets(const string& name):nickname{name}{}
    string get_nickname()const { return nickname; }
    virtual string  talk() = 0;

private:
    string nickname;
};

class PetCats :public MachinePets {
public:
    PetCats(const string& name):MachinePets(name) {
    }
    
    string  talk() {
        return "miao wu~";
    }
};

class PetDogs :public MachinePets{
public:
    PetDogs(const string& name) :MachinePets(name) {
    }

    string  talk() {
        return "wang wang~";
    }
};

task3.cpp:

#include"pets.hpp"
#include<iostream>
#include<vector>

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();
}

运行结果：

实验四：

film.hpp:

#pragma once
#include<iostream>
#include<string>
#include<iomanip>

using namespace std;

class Film {
public:
    Film() = default;
    int  getYear()const { return year; }

    friend  istream& operator>>(istream& in, Film& f);
    friend  ostream& operator<<(ostream& out, Film& f);
private:
    string name;
    string director;
    string area;
    int  year;
};

istream& operator>>(istream& in, Film &f) {
    cout << "录入片名："; in >> f.name;
    cout << "录入导演："; in >> f.director;
    cout << "录入制片国家/地区："; in >> f.area;
    cout << "录入上映年份："; in >> f.year;

    return in;
}

ostream& operator<<(ostream& out, Film &f) {
    out << left    
        << setw(20) << f.name       
        << setw(20) << f.director   
        << setw(20) << f.area        
        << setw(6) << f.year;

    return out;
}

task4.cpp:

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

bool compare_by_year(const Film &f1,const Film &f2) {
    return f1.getYear() < f2.getYear();
}

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);
    }
    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();
}

运行结果：

实验五：

代码：
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 } {};
    Complex(const Complex<T>& c) {
        this->real = c.real;
        this->imag = c.imag;
    }

    Complex operator+=(const Complex<T>& c) {
        this->real += c.real;
        this->imag += c.imag;
        return *this;
    }

    T get_real() const { return real; }
    T get_imag() const { return imag; }

    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<T>& c){
        in >> c.real >> c.imag;
        return in;
    }
    friend ostream& operator<<(ostream& out, const Complex& c){
        out << c.real << (c.imag >= 0 ? "+" : "") << c.imag << "i";
        return out;
    }

private:
    T real;
    T imag;
};

task5.cpp:

#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();
}

运行结果：

实验六：

 

代码：

date.h:

#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;
    }
};

date.cpp:

#include "date.h"
#include <iostream>
#include <cstdlib>
using namespace std;

namespace {
    const int DAYS_BEFORE_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 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
    if (isLeapYear() && month > 2) totalDays++;
}

int Date::getMaxDay() const {
    if (isLeapYear() && month == 2)
        return 29;
    else return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
}

void Date::show() const {
    cout << getYear() << "-" << getMonth() << "-" << getDay();
}

accumulator.h:

#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 = value;
        sum = 0;
    }
};

account.h:

#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;
};

account.cpp:

#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) {
    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 enough 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();
}

task6.cpp:

#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;
}

运行结果：