实验5 继承和多态

实验三

test.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();
}

pets.hpp

#pragma once

#include <iostream>
#include <string>

using namespace std;

class MachinePets {
public:
    MachinePets(const string &s = "");
    string get_nickname() const;

public:
    virtual string talk() const = 0;

protected:
    string nickname;
};

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

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

class PetCats: public MachinePets{
public:
    PetCats(const string &s = "");

public:
    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 = "");

public:
    string talk() const override;
};

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

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

实验结果

实验四

test.cpp

#include "C:\Users\DELL\Documents\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);
    }

    
    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();
}

film.hpp

#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();
 }

 实验结果

  实验五

test.cpp

#include "C:\Users\DELL\Documents\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();
}

Complex.hpp

#pragma once
#include <iostream>

using namespace std;

template<typename T>
class Complex{
private:
T imag, real;
public:
Complex() : imag{0}, real{0} {}
Complex(T i, T r) : imag{i}, real{r} {}
Complex(const Complex &c) {
imag = c.imag;
real = c.real;
}
T get_imag() const { return imag; }
T get_real() const { return real; }

friend istream& operator>>(istream &in, Complex &c) {
in >> c.imag >> c.real;
return in;
}
friend ostream& operator<<(ostream &out, const Complex &c) {
if(c.real >= 0){
out << c.imag <<" + " << c.real << 'i';
}
else
out << c.imag <<" - " << -c.real << 'i';
return out;
}
friend void operator+=(Complex &c1, Complex c2) {
c1.imag += c2.imag;
c1.real += c2.real;
}
friend Complex operator+(Complex c1, Complex c2) {
Complex c;
c.imag = c1.imag + c2.imag;
c.real = c1.real + c2.real;
return c;
}
friend bool operator==(Complex c1, Complex c2) {
if(c1.imag == c2.imag && c1.real == c2.real)
return true;
else
return false;

}
};

实验结果

 

实验六

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;
    }
};

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;
        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;
}

实验结果

 因为账户的公共操作都为虚函数，因此可以通过基类的指针来执行操作，各种账户对象通过一个基类指针数组来访问，这提供了极大的方便，我们可以通过统一的方式来操作