实验五 c++

任务三：

Pet.hpp:

#pragma once

#include <iostream>
#include <string>

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

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

};

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

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

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

　　

task3.cpp:

#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();
}

　　

实验结果截图：

 

任务四：

film.hpp:

#pragma once

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

using namespace std;



class Film
{
public:


   
    int  get_year() const {
        return year;
    }
    friend ostream& operator<<(ostream& os, const Film& film);
    friend istream& operator>>(istream& is, Film& film);

private:
    string name;
    string director;
    string area;
    int year;
};
ostream& operator<<(ostream& out, const Film& film)
{
    out << setw(10) << left << film.name << setw(10) << left << film.director << setw(10) << left << film.area << setw(10) << left << film.year;
    return out;
}

istream& operator>>(istream& in, Film& film)
{
    cout << "录入片名：";
    in >> film.name;
    cout <<"录入导演：";
    in>>film.director;
    cout << "录入地区：";
    in>>film.area;
    cout << "录入年份：";
    in>>film.year;
    return in;
    
}       

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

　　

task4.cpp;

#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();
}

　　

实验结果截图:

 

任务五：

Complex.hpp:

#pragma once
#include <iostream>
#include <cmath>

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

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

    Complex& operator+=(const Complex& c) {
        real += c.real;
        imag += c.imag;
        return *this; // 返回自身引用
    }
    // 获取实部
    T get_real() const {
        return real;
    }

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

    // 重载加法运算符
    Complex operator+(const Complex& other) const {
        return Complex(real + other.real, imag + other.imag);
    }
    bool operator==(const Complex& other) const {
        return (real == other.real) && (imag == other.imag);
    }
    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& os, const Complex& c) {
        os << c.real << " + " << c.imag << "i";
        return os;
    }


};

　　

task.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();
}

　　

实验结果截图:

 任务六:

date.h:

//date.h
#ifndef DATE_H
#define 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;
	}
};
#endif // DATE_H

　　

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:

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

　　

account.h

#ifndef ACCOUNT_H
#define 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 getTotal() { 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) = 0;
	virtual void show()const;

};
class SavingsAccount : public Account {//储账户类
private:
	Accumulator acc; //辅助计算利息的累加器
	double rate; //存款的年利率

public:
	//构造函数
	SavingsAccount(const Date& date, const std::string& id, double rate);
	double getRate() const { return rate; }

	//存入现金
	void deposit(const Date& date, double amount, const std::string& desc);

	//取出现金
	void withdraw(const Date& date, double amount, const std::string& desc);
	void settle(const Date& date); //结算利息，每年1月1日调用一次该函数
};

class CreditAccount :public Account {//信用账户类
private:
	Accumulator acc; //辅助计算利息的累加器
	double credit; //信用额度
	double rate; //欠款的日利率
	double fee; //信用卡年费

	double getDebt() const { //获得欠款额
		double balance = getBalance();
		return (balance < 0 ? balance : 0);
	}

public:
	//构造函数
	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 {
		//获得可用信用
		if (getBalance() < 0)
			return credit + getBalance();
		else
			return credit;
	}
	//存入现金
	void deposit(const Date& date, double amount, const std::string& desc);
	//取出现金
	void withdraw(const Date& date, double amount, const std::string& desc);
	void settle(const Date& date); //结算利息和年费，每月1日调用一次该函数
	void show() const;
};
#endif // _ACCOUNT_H_

　　

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) {
    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::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':
            // 查询各账户信息

            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;

           
     
}

　　

实验结果截图:

 经过改进,对账户的各种操作都可以通过基类的指针来调用，增加了程序的灵活性。

利用运算符重载后的代码更具可读性。