实验5 继承和多态

实验任务1

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() = 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() override;
    void read();

private:
    string author;
};

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

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

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

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

public:
    void publish() override;
    void watch();

private:
    string director;
};

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

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

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

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

public:
    void publish() override;
    void listen();

private:
    string artist;
};

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

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

void Music::listen() {
    cout << "Listening to music: " << name << " by " << artist << endl;
}

task1.cpp

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

using std::vector;

void func(Publisher *ptr) {
    cout << "pointer type: " << typeid(ptr).name() << endl;
    cout << "RTTI type: " << typeid(*ptr).name() << endl;
    
    ptr->publish();
}

void test() {
    Publisher *ptr;

    cout << "测试1: \n";
    Book book{"Harry Potter", "J.K. Rowling"};
    ptr = &book;
    func(ptr);
    book.read();

    cout << "\n测试2: \n";
    Film film{"The Godfather", "Francis Ford Coppola"};
    ptr = &film;
    func(ptr);
    film.watch();

    cout << "\n测试3: \n";
    Music music{"Blowing in the wind", "Bob Dylan"};
    ptr = &music;
    func(ptr);
    music.listen();
}

int main() {
    test();
}

运行结果

 

实验任务2

complex.hpp

#pragma once

#include <iostream>

class Complex {
public:
    Complex(double r = 0, double i = 0): real{r}, imag{i} {}
    Complex(const Complex &c): real{c.real}, imag{c.imag} {}
    ~Complex() = default;

public:
    double get_real() const { return real; }
    double get_imag() const { return imag; }

    Complex& operator+=(const Complex &c);

    friend Complex operator+(const Complex &c1, const Complex &c2);
    friend bool operator==(const Complex &c1, const Complex &c2);
    
    friend std::ostream& operator<<(std::ostream &os, const Complex &c);
    friend std::istream& operator>>(std::istream &is, Complex &c);

private:
    double real, imag;
};

Complex& Complex::operator+=(const Complex &c) {
    real += c.real;
    imag += c.imag;

    return *this;
}

Complex operator+(const Complex &c1, const Complex &c2) {
    return Complex(c1.get_real() + c2.get_real(),
                   c1.get_imag() + c2.get_imag());
}

bool operator==(const Complex &c1, const Complex &c2) {
    return (c1.get_real() == c2.get_real() && c1.get_imag() == c2.get_imag());
}

std::ostream& operator<<(std::ostream &os, const Complex &c) {
    if(c.imag >= 0)
        os << c.real << " + " << c.imag << "i";
    else
        os << c.real << " - " << -c.imag << "i";

    return os;
} 

std::istream& operator>>(std::istream &is, Complex &c) {
    is >> c.real >> c.imag;

    return is;
}

task2.cpp

#include <iostream>
#include "complex.hpp"

void test() {
    using namespace std;

    Complex c1;
    cout << "Enter c1: ";
    cin >> c1;
    cout << "c1 = " << c1 << endl;

    Complex c2{1.5}, c3{1.5, 3}, c4{c3};
    cout << "c2 = " << c2 << endl;
    cout << "c3 = " << c3 << endl;
    cout << "c4 = " << c4 << endl;
    cout << "c3 == c4: " << boolalpha << (c3 == c4) << endl;

    cout << "c1 + c2 = " << c1 + c2 << endl;
    c1 += c2;
    cout << "c1 = " << c1 << endl;
    cout << c1.get_real() << " " << c1.get_imag() << endl;
}

int main() {
    test();
}

运行结果

 

实验任务3

pets.hpp

#include<iostream>
#include<string>
using namespace std;
class MachinePets
{
private:
    string nickname;
public:
    MachinePets(const string s) :nickname{ s } {}
    string get_nickname() const { return nickname; }
    virtual string talk() = 0;
};
class PetCats :public MachinePets
{
public:
    PetCats(const string s) :MachinePets{ s } {}
    string talk()
    {
        return "miao wu~";
    }


};
class PetDogs:public MachinePets
{
public:
    PetDogs(const string s) :MachinePets{ s } {}
    string talk()
    {
        return "wang wang~";
    }

};

task3.cpp

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

void play(MachinePets &obj) {
    std::cout << obj.get_nickname() << " says " << obj.talk() << std::endl;
}

void test() {
    PetCats cat("miku");
    PetDogs dog("da huang");

    play( cat );
    play( dog );
}

int main() {
    test();
}

运行结果

 

实验任务4

 Person.hpp

#include<iostream>
#include<string>
#include <iomanip>
using namespace std;
class Person
{
private:
    string name;
    string telephone;
    string email;
public:
    Person(string name, string telephone)
    {
        this->name = name;
        this->telephone = telephone;
    }
    Person()
    {
        this->name = name; this->telephone = telephone; this->email = email;
    }
    Person(const Person &s);
    void update_telephone()
    {
            cout << "输入电话号码：";
            cout<< telephone;
            cout << endl << "电话号码更新成功" << endl;
    }
    void update_email();
    friend  std::ostream& operator<<(std::ostream& out, const Person& t)
    {
            out << "name:" << t.name << endl;
            out << "telephone:" << t.telephone << endl;
            out << "email:" << t.email << endl;
            return out;
    }
    friend std::istream& operator>>(std::istream& in,  Person& t)
    {
        in >> t.name >> t.telephone >> t.email;
        cout << endl;
        return in;
    }
    friend bool operator==(const Person& s1, const Person& s2)
    {
        if (s1.name == s2.name && s1.telephone == s2.telephone && s1.email == s2.email)
            return 1;
        else
            return 0;
    }
};
Person::Person(const Person &s)
{
    name = s.name; telephone =s.telephone; email = s.email;
}

task4.cpp

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

void test() {
    using namespace std;

    vector<Person> phone_book;
    Person p;

    cout << "输入一组联系人的联系方式，E直至按下Ctrl+Z终止\n";
    while(cin >> p)
        phone_book.push_back(p);

    cout << "\n更新phone_book中索引为0的联系人的手机号、邮箱:\n";
    phone_book.at(0).update_telephone();
    phone_book.at(0).update_email();

    cout << "\n测试两个联系人是否是同一个:\n";
    cout << boolalpha << (phone_book.at(0) == phone_book.at(1)) << endl;
}

int main() {
    test();
}

运行结果

 

实验任务5

date.h

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

#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; sum = 0;
    }
    void reset(const Date& date, double value)
    {
        lastDate = date; this->value = value;
    }
};

account.h

#include"date.h"
#include"accumulator.h"
#include<string>
class Account
{
private:
    std::string id;
    double balance;
    static double total;
protected:
    Account(const Date& date, const std::string& id);
    void record(const Date& date, double amount, const std::string& desc);
    void error(const std::string& msg) const;
public:
    const std::string& getId() const { return id; }
    double getBalance() const { return balance; }
    static double getToal() { return total; }
    virtual void deposit(const Date& date, double amount, const std::string& desc) = 0;
    virtual void withdraw(const Date& date, double amount, const std::string& desc) = 0;
    virtual void settle(const Date& date);
    virtual void show() const;
};
class SavingsAccount :public Account
{
private:
    Accumulator acc;
    double rate;
public:
    SavingsAccount(const Date& date, const std::string& id, double rate);
    double getRate() const { return rate; }
    void deposit(const Date& date, double amount, const std::string& desc);
    void withdraw(const Date& date, double amount, const std::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 std::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 std::string& desc);
    void withdraw(const Date& date, double amount, const std::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 std::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 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();
}

8.8.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::getToal() << "\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