实验五 继承和多态

任务3：

#ifndef PETS_HPP
#define PETS_HPP

#include <string>
#include <iostream>

class MachinePets {
protected:
    std::string nickname;  

public:
    MachinePets(const std::string& s) : nickname(s) {}

    virtual std::string talk() = 0;

    std::string get_nickname() const {
        return nickname;
    }

    virtual ~MachinePets() {}
};

class PetCats : public MachinePets {
public:
    PetCats(const std::string& s) : MachinePets(s) {}

    std::string talk() override {
        return "喵喵";
    }
};

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

    std::string talk() override {
        return "汪汪";
    }
};

#endif 

#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();
}

运行结果：

 

 

 

 

任务4：

#ifndef FILM_HPP
#define FILM_HPP

#include <iostream>
#include <string>

class Film {
private:
    std::string title;        
    std::string director;     
    std::string country;      
    int year;                 

public:
    Film() : title(""), director(""), country(""), year(0) {}

    Film(const std::string& t, const std::string& d, const std::string& c, int y)
        : title(t), director(d), country(c), year(y) {}

    int get_year() const {
        return year;
    }

    friend std::istream& operator>>(std::istream& is, Film& f) {
        is.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
        
        std::cout << "请输入片名: ";
        std::getline(is, f.title); 
        
        std::cout << "请输入导演: ";
        std::getline(is, f.director);
        
        std::cout << "请输入制片国家/地区: ";
        std::getline(is, f.country);
        
        std::cout << "请输入上映年份: ";
        is >> f.year;

        return is;
    }

    friend std::ostream& operator<<(std::ostream& os, const Film& f) {
        os << "片名: " << f.title << std::endl;
        os << "导演: " << f.director << std::endl;
        os << "制片国家/地区: " << f.country << std::endl;
        os << "上映年份: " << f.year << std::endl;
        return os;
    }
};

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

#endif 

#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();
}

运行结果：

 

 

 

 

 

任务5：

#ifndef COMPLEX_HPP
#define COMPLEX_HPP

#include <iostream>

template <typename T>
class Complex {
private:
    T real;  
    T imag;  

public:
    Complex() : real(0), imag(0) {}
    Complex(T r, T i) : real(r), imag(i) {}
    T get_real() const { return real; }
    T get_imag() const { return imag; }
    Complex& operator+=(const Complex& other) {
        this->real += other.real;
        this->imag += other.imag;
        return *this;
    }
    Complex operator+(const Complex& other) const {
        return Complex(this->real + other.real, this->imag + other.imag);
    }
    bool operator==(const Complex& other) const {
        return this->real == other.real && this->imag == other.imag;
    }
    friend std::istream& operator>>(std::istream& is, Complex& c) {
        is >> c.real >> c.imag;
        return is;
    }
    friend std::ostream& operator<<(std::ostream& os, const Complex& c) {
        os << c.real << " + " << c.imag << "i";
        return os;
    }
};

#endif 

#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：

 

 

 

 

任务6：

#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 + years / 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();
}

#ifndef __ACCUMULATOR_H__
#define __ACCUMULATOR_H__
#include"date.h"
class Accumulator {//将某a个数值按日累加
private:
    Date lastDate;//上次变更数值的时期
    double value;//数值的当前值
    double sum;//数值按日累加之和
public:
    double getSum(const Date &date)const {
        return sum + value * (date - lastDate);
    }
    Accumulator(const Date &date,double value):lastDate(date),value(value),sum(0){}//构造函数，date为开始累加的日期，value为初始值
    void change(const Date& date, double value) {
        sum = getSum(date);
        lastDate = date; this->value = value;//在date将数值改为value
    }
    void reset(const Date& date, double value) {
        lastDate = date; this->value = value; sum = 0;//初始化，将日期变为date，数值变为value，累加器清零
    }
};
#endif

#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) {
    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();
}

#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 + years / 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();
}

#include"account.h"
#include<iostream>
using namespace std;
int main() {
    Date date(2008, 11, 1);//起始日期
    //建立几个账户
    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*);//账户总数 
    cout << "(d)deposit (w)withdraw (s)show (c)change day (n)next month (e)exit" << endl;
    char cmd;
    do {
        //显示日期和总金额
        date.show();
        cout << "\tTotal:" << Account::getTotal() << "\tcommand>";
        int index, day;
        double amount;
        string desc;
        cin >> cmd;
        switch (cmd) {
        case 'd'://存入现金
            cin >> index >> amount;
            getline(cin, desc);
            accounts[index]->deposit(date, amount, desc);
            break;
        case 'w'://取出现金
            cin >> index >> amount;
            getline(cin, desc);
            accounts[index]->withdraw(date, amount, desc);
            break;
        case 's'://查询各账户信息
            for (int i = 0; i < n; i++) {
                cout << "[" << i << "]";
                accounts[i]->show();
                cout << endl;
            }
            break;
        case 'c'://改变日期
            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'://进入下个月
            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：