实验

实验任务3： pets.hpp

#pragma once
#include <iostream>
#include <string>
using namespace std;
class MachinePets
{
public:
    MachinePets(const string &s) : nickname{s} {}
    virtual string talk() const = 0;
    string get_nickname() const { return nickname; }

protected:
    string nickname;
};

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

    string talk() const override
    {
        return "Woof";
    }
};

task3.cpp

#include "pets.hpp"
#include <iostream>
#include <vector>

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;
    }

    for (auto &ptr : pets)
    {
        delete ptr;
    }
}

int main()
{
    test();
    return 0;
}

运行结果：

实验任务4：

fim.hpp

#pragma once
#include <iostream>
#include <string>
using std::istream;
using std::ostream;
using std::string;

// 电影类 Film
class Film
{
public:
    // 默认构造函数
    Film() = default;

    // 带参数的构造函数
    Film(string name, string director, string country, int year)
        : name_(name), director_(director), country_(country), year_(year) {}

    // 重载输入运算符>>
    friend istream &operator>>(istream &in, Film &film)
    {
        std::cout << "录入片名: ";
        in >> film.name_;
        std::cout << "录入导演: ";
        in >> film.director_;
        std::cout << "录入制片国家/地区: ";
        in >> film.country_;
        std::cout << "录入上映年份: ";
        in >> film.year_;
        return in;
    }

    // 重载输出运算符<<
    friend ostream &operator<<(ostream &out, const Film &film)
    {
        out << film.name_ << "     "
            << film.director_ << "     "
            << film.country_ << "     "
            << film.year_ << "\n";
        return out;
    }

    // 辅助函数，用于比较电影的发行年份
    bool compare_by_year(const Film &other) const
    {
        return year_ < other.year_;
    }

private:
    string name_;     // 片名
    string director_; // 导演
    string country_;  // 制片国家/地区
    int year_;        // 上映年份
};

task4.cpp

#include "film.hpp"
#include <algorithm>
#include <iostream>
#include <vector>

// 比较函数，用于排序
bool compare_by_year(const Film &f1, const Film &f2)
{
    return f1.compare_by_year(f2);
}

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 (const auto &f : film_lst)
    {
        cout << f << endl;
    }
}

int main()
{
    test();
    return 0;
}

运行结果：

 

实验任务5：

Complex.hpp

#pragma once
#include <iostream>
#include <vector>

using namespace std;

template <typename T>

class Complex
{
public:
    T real;
    T imag;
    Complex(T real = 0, T imag = 0) : real{real}, imag{imag} {}

    T get_real() const { return real; }
    T get_imag() const { return imag; }
    Complex &operator+=(const Complex &r)
    {

        real += r.real;
        imag += r.imag;
        return *this;
    }
    Complex operator+(const Complex &r) const
    {
        return Complex(real + r.real, imag + r.imag);
    }
    bool operator==(const Complex &r) const
    {
        return (real == r.real) && (imag == r.imag);
    }
    friend istream &operator>>(istream &is, Complex &c)
    {
        is >> c.real >> c.imag;
        return is;
    }

    friend ostream &operator<<(ostream &os, const Complex &c)
    {
        os << c.real << " + " << c.imag << "i";
        return os;
    }
};

task5.cpp

#include "Complex.hpp"
#include <iostream>

using std::boolalpha;
using std::cin;
using std::cout;
using std::endl;

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6：

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;
     }
 };

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

 #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;
     }
 };

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 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;
 };

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 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();
 }

task6.cpp

 1 #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：