cpp 實驗5

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



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();
}

hpp
#pragma once
#include<iostream>
#include<iomanip>
using namespace std;
class film {
private:
    string name, director, area, time;
public:
    film(const string& name="", const string& director="", const string& area="", const string& time="");
    friend ostream& operator<<(ostream& out, const film& f);
    friend istream& operator>>(istream& in, film& f);
    string get_year()const;
};
film::film(const string& name, const string& director, const string& area, const string& time) {
    this->name = name;
    this->director = director;
    this->area = area;
    this->time = time;
}
string film::get_year()const {
    return time;
}
ostream& operator<<(ostream& out, const film& f) {
    out << f.name<< setw(15) << f.director <<setw(10) << f.area << setw(10) << f.time << endl;
    return out;
}
istream& operator>>(istream& in,film& f) {
    in >> f.name >> f.director >> f.area >> f.time;
    return in;
}
bool compare_by_year(const film& f1, const film& f2) {
    return f1.get_year() < f2.get_year();
}



cpp
#include "film.hpp"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
void test() {
    using namespace std;

    int n;
    cout << "輸入電影數目: ";
    cin >> n;
    cout << "錄入" << n << "部影片資訊" << endl;
    vector<film> film_lst;
    for (int i = 0; i < n; ++i) {
        film f;
        cout << string(20, '-') << "第" << i + 1 << "部影片錄入" << string(20,
            '-') << endl;
        cin >> f;
        film_lst.push_back(f);
    }
    // 按發行年份升序排序
    sort(film_lst.begin(), film_lst.end(), compare_by_year);
    cout << string(20, '=') + "電影資訊(按發行年份)" + string(20, '=') << endl;
    for (auto& f : film_lst)
        cout << f << endl;
}
int main() {
    test();
}

hpp
#pragma once
#include <iostream>
using namespace std;
template <typename T>
class Complex {
public:
    Complex(const T& r = 0, const T& i = 0) : real{ r }, imag{ i } {}
    Complex operator+=(const Complex& c) {
        real += c.real;
        imag += c.imag;
        return *this;
    }
    friend Complex operator+(const Complex& c1, const Complex& c2) {
        return Complex<T>(c1.real + c2.real, c1.imag + c2.imag);
    }
    friend bool operator==(const Complex& c1, const Complex& c2) {
        return c1.real == c2.real && c1.imag == c2.imag;
    }
    friend ostream& operator<<(ostream& out, const Complex& c) {
        if (c.imag >= 0)
            out << c.real << "+" << c.imag << "i";
        else
            out << c.real << "-" << -c.imag << "i";
        return out;
    }
    friend istream& operator>>(istream& in, Complex& c) {
        in >> c.real >> c.imag;
        return in;
    }
    T get_real() const {
        return real;
    }
    T get_imag() const {
        return imag;
    }

private:
    T real;
    T imag;
};



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 << "自定義類别範本Complex測試1: " << endl;
    test1();
    cout << endl;
    cout << "自定義類别範本Complex測試2: " << endl;
    test2();
}

date.h
#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;
    }
};


accmulator.h
#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

#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;
};


date.cpp
#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();
}


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) {
    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();
}

task6.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':
            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;
}

在基類賬戶中將公共操作皆宣告為虛擬函式，因此可以透過基類指標來執行各種操作，因而各種型別的賬戶物件都可以透過一個基類指標的陣列來訪問，這提供了極大的便利，使我們可以透過統一的方式來操作各個賬戶，因而從cin輸入所執行的操作就變得非常方便了。

在本例的主程式中我們必須將幾個賬戶的構造在程式中寫死，而不允許使用者隨時動態的新增新的賬戶。