实验5 继承和多态

实验任务3
程序源码：
pets.hpp:

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#pragma once

#include <iostream>
#include <string>

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

class MachinePets {
public:
	MachinePets(const string s);
	virtual string talk() const =0;
	virtual string get_nickname() const = 0;
protected:
	string nickname;
};

MachinePets::MachinePets(const string s) : nickname{ s } {}

class PetCats: public MachinePets {
public:
	PetCats(const string& s);
	string talk() const override;
	string get_nickname() const override;
};

PetCats::PetCats(const string& s):MachinePets(s){}

string PetCats::talk() const {
	return "miao wu~";
}

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

class PetDogs: public MachinePets {
public:
	PetDogs(const string& s);
	string talk() const override;
	string get_nickname() const override;
};

PetDogs::PetDogs(const string& s) :MachinePets(s) {}

string PetDogs::talk() const {
	return "wang wang~" ;
}

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

task3.cpp:

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#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();
}

运行测试截图:

实验任务4
程序源码：
film.hpp:

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#pragma once

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

class Film {
public:
    Film(const std::string& s = "", const std::string& d = "", const std::string& a = "", int t = 0);
    ~Film() = default; 

    std::string getTitle() const { return title; }
    int getYear() const { return year; } 

    friend std::ostream& operator<<(std::ostream& out, const Film& f);
    friend std::istream& operator>>(std::istream& in, Film& f);

private: 
    std::string title;
    std::string director;
    std::string country;
    int year;
};

// film.cpp
#include "film.hpp"

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

std::ostream& operator<<(std::ostream& out, const Film& f) {
    out<<std::setw(10) << f.title << std::setw(10) << f.director << std::setw(12) << f.country << std::setw(6) <<f.year;
    return out;
}

std::istream& operator>>(std::istream& in, Film& f) {
    std::cout << "片名: "; in >> f.title; 
    std::cout << "导演: "; in >> f.director ;
    std::cout << "制片国家/地区: "; in>> f.country; 
    std::cout << "上映年份: "; in >> f.year ; 
    
    return in;
}

bool compare_by_year(const Film& a, const Film& b) {
    return a.getYear() < b.getYear(); 
}

task4.cpp:

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#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();
}

运行测试截图:

实验任务5
程序源码：
Complex.hpp:

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#pragma once

#include <iostream>

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

public:
    Complex(T r = 0, T i = 0) : real(r), imag(i) {}

    T get_real() const {
        return real;
    }

    T get_imag() const {
        return imag;
    }

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

    Complex<T> operator+(const Complex<T>& other) const {
        return Complex<T>(real + other.real, imag + other.imag);
    }

    bool operator==(const Complex<T>& other) const {
        return real == other.real && imag == other.imag;
    }

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

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

task5.cpp:

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#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();
}

运行测试截图:

实验任务6
date.h：

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#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;
}

date.cpp：

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#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();
}

accumulator.h：

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#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;
    }
};

account.h：

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#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 amoount, 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：

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#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 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();
}

8_8.cpp：

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#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;
}

运行测试截图: