实验5 继承和多态

实验任务三

源码

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

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

//电子宠物类
class MachinePets {
private:
    string nickname;
public:
    MachinePets(const string&s="");
    string get_nickname() const;
    virtual string talk()=0;
};

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

}

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

//猫类
class PetCats :public MachinePets {
public:
    PetCats(const string& s = "");
    string talk();
};

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

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

//狗类
class PetDogs :public MachinePets {
public:
    PetDogs(const string& s = "");
    string talk();
};

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

}

string PetDogs::talk() {
    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();
}

运行结果

 

 

 

实验任务四

源码

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

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

class Film {
private:
    string title;
    string director;
    string country;
    int year;
public:
    Film():title(""),director(""),country(""),year(0){}
    Film(const string&t,const string&d,const string c,const int y)
        :title(t),director(d),country(c),year(y){}

    friend std::istream& operator>>(std::istream &is, Film& film);
    friend std::ostream& operator<<(std::ostream &os, Film& film);

    int getyear()const;

};

std::istream& operator>>(std::istream &is, Film& film){
    cout << "录入片名："; 
    is >> film.title;
    cout << "录入导演："; 
    is >> film.director;
    cout << "录入制片国家/地区："; 
    is >> film.country;
    cout << "录入上映年份："; 
    is >> film.year; 
    return is;
}

std::ostream& operator<<(std::ostream &os, Film& film) {
    os << std::left;
    os << setw(15) << film.title
        << setw(15) << film.director
        << setw(15) << film.country 
        << setw(15) << film.year<<endl;
    return os;
}

int Film::getyear() const{
    return year;
}

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

#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

 

 

 

实验任务五

源码

#pragma once

#include <iostream>

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

public:
    // 默认构造函数
    Complex(T r = 0, T i = 0) : real(r), imag(i) {}

    // 拷贝构造函数
    Complex(const Complex& other) : real(other.real), imag(other.imag) {}

    // 获取实部
    T get_real() const { return real; }

    // 获取虚部
    T get_imag() const { return imag; }

    // 重载+运算符
    Complex operator+(const Complex& other) const {
        return Complex(real + other.real, imag + other.imag);
    }

    // 重载+=运算符
    Complex& operator+=(const Complex& other) {
        real += other.real;
        imag += other.imag;
        return *this;
    }

    // 重载==运算符
    bool operator==(const Complex& other) const {
        return real == other.real && imag == other.imag;
    }

    // 重载输入流运算符
    friend std::istream& operator>>(std::istream& in, Complex& c) {
        in >> c.real >> c.imag;
        return in;
    }

    // 重载输出流运算符
    friend std::ostream& operator<<(std::ostream& out, const Complex& c) {
        out << c.real << (c.imag >= 0 ? " + " : " - ") << std::abs(c.imag) << "i";
        return out;
    }
};

#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

 

 

 

实验任务六

源码

#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 "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();
}

#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;
    }
};

#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;
};

#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 "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