实验五 继承和多态
实验一:
代码:
publisher.hpp:
1 #pragma once 2 3 #include<iostream> 4 #include<string> 5 6 using std::cout; 7 using std::endl; 8 using std::string; 9 10 class Publisher { 11 public: 12 Publisher(const string& s = ""); 13 14 public: 15 virtual void publish()const = 0; 16 virtual void use()const = 0; 17 18 protected: 19 string name; 20 }; 21 22 Publisher::Publisher(const string&s):name{s}{} 23 24 class Book :public Publisher { 25 public: 26 Book(const string& s = "", const string& a = ""); 27 28 public: 29 void publish()const override; 30 void use()const override; 31 32 private: 33 string author; 34 }; 35 36 Book::Book(const string&s,const string&a):Publisher{s},author{a}{} 37 38 void Book::publish()const { 39 cout << "Publishing book: 《" << name << "》by" << author << endl; 40 } 41 42 void Book::use()const { 43 cout << "Reading book:" << name << "by" << author << endl; 44 } 45 46 class Film :public Publisher { 47 public: 48 Film(const string& s = "", const string& d = ""); 49 50 public: 51 void publish()const override; 52 void use()const override; 53 54 private: 55 string director; 56 }; 57 58 Film::Film(const string &s,const string&d):Publisher{s},director{d}{} 59 60 void Film::publish()const { 61 cout << "Publishing film:<" << name << ">directed by" << director << endl; 62 } 63 64 void Film::use()const { 65 cout << "watching film:" << name << "directed by" << director << endl; 66 } 67 68 class Music :public Publisher { 69 public: 70 Music(const string& s = "", const string& a = ""); 71 72 public: 73 void publish()const override; 74 void use()const override; 75 76 private: 77 string artist; 78 }; 79 80 Music::Music(const string& s, const string& a) :Publisher{ s }, artist{ a } { 81 } 82 83 void Music::publish()const { 84 cout << "Publishing music<" << name << ">by" << artist << endl; 85 } 86 87 void Music::use()const { 88 cout << "Listening to music:" << name << "by" << artist << endl; 89 }
task1.cpp:
1 #include"publisher.hpp" 2 #include<vector> 3 #include<typeinfo> 4 5 using std::vector; 6 7 void test() { 8 vector<Publisher*>v; 9 10 v.push_back(new Book("Harry Ptter", "J.K.Rowling")); 11 v.push_back(new Film("The Godfather", "Francis Ford Coppola")); 12 v.push_back(new Music("Blowing in the wind", "Bob Dylan")); 13 14 for (auto& ptr : v) { 15 cout << "pointer type:" << typeid(ptr).name() << endl; 16 17 cout << "RTTI type:" << typeid(*ptr).name() << endl; 18 19 ptr->publish(); 20 ptr->use(); 21 cout << endl; 22 } 23 } 24 25 int main() { 26 test(); 27 }
运行结果:
实验二:
代码:
book.hpp:
1 #pragma once 2 3 #include<iostream> 4 #include<string> 5 #include<iomanip> 6 7 8 using std::ostream; 9 using std::endl; 10 using std::string; 11 using std::setw; 12 using std::left; 13 14 15 class Book { 16 public: 17 Book(const string&name,const string&author,const string&translator,const string &isbn,float ptice); 18 19 friend ostream& operator<<(ostream& out, const Book& book); 20 21 private: 22 string name; 23 string author; 24 string translator; 25 string isbn; 26 float price; 27 }; 28 29 Book::Book(const string& name, const string& author, const string& translator, const string& isbn, float price) { 30 this->name = name; 31 this->author = author; 32 this->translator = translator; 33 this->isbn = isbn; 34 this->price = price; 35 } 36 37 ostream& operator<<(ostream& out, const Book& book) { 38 out << left; 39 out << setw(15) << "书名:" << book.name << endl 40 << setw(15) << "作者:" << book.author << endl 41 << setw(15) << "译者:" << book.translator << endl 42 << setw(15) << "定价:" << book.price; 43 44 return out; 45 }
booksale.hpp:
1 #pragma once 2 3 #include"book.hpp" 4 #include<iostream> 5 #include<string> 6 #include<iomanip> 7 8 using std::string; 9 using std::cout; 10 using std::endl; 11 using std::setw; 12 13 class BookSale { 14 public: 15 BookSale(const Book& b, float price, int amount); 16 int get_amount()const; 17 18 friend ostream& operator<<(ostream& out, const BookSale& item); 19 20 private: 21 Book rb; 22 float sales_price; 23 int sales_amount; 24 float revenue; 25 }; 26 27 BookSale::BookSale(const Book& b, float price, int amount) :rb{ b }, sales_price(price), sales_amount{ amount } { 28 revenue = sales_amount * sales_price; 29 } 30 31 int BookSale::get_amount()const { 32 return sales_amount; 33 } 34 35 ostream& operator<<(ostream& out, const BookSale& item) { 36 out << left; 37 out << item.rb << endl 38 << setw(15) << "售价:" << item.sales_price << endl 39 << setw(15) << "销售数量:" << item.sales_amount << endl 40 << setw(15) << "营收:" << item.revenue; 41 42 return out; 43 }
task2.cpp:
1 #include"booksale.hpp" 2 #include<iostream> 3 #include<string> 4 #include<vector> 5 #include<algorithm> 6 7 bool compare_by_amount(const BookSale& x1, const BookSale& x2) { 8 return x1.get_amount() > x2.get_amount(); 9 } 10 11 void test() { 12 using namespace std; 13 14 vector<BookSale>sales_lst; 15 16 int books_number; 17 cout << "录入图书数量:"; 18 cin >> books_number; 19 20 cout << "录入图书销售记录" << endl; 21 for (int i = 0; i < books_number; ++i) { 22 string name, author, translator, isbn; 23 float price; 24 cout << string(20, '-') << "第" << i + 1 << "本图书信息录入" << string(20, '-') << endl; 25 cout << "录入书名:"; cin >> name; 26 cout << "录入作者:"; cin >> author; 27 cout << "录入译者:"; cin >> translator; 28 cout << "录入isbn:"; cin >> isbn; 29 cout << "录入定价:"; cin >> price; 30 31 Book book(name, author, translator, isbn, price); 32 float sales_price; 33 int sales_amount; 34 35 cout << "录入售价:"; cin >> sales_price; 36 cout << "录入销售数量"; cin >> sales_amount; 37 38 BookSale record(book, sales_price, sales_amount); 39 sales_lst.push_back(record); 40 } 41 42 sort(sales_lst.begin(), sales_lst.end(), compare_by_amount); 43 44 cout << string(20, '=') << "图书销售统计" << string(20, '=') << endl; 45 for (auto& t : sales_lst) { 46 cout << t << endl; 47 cout << string(40, '-') << endl; 48 } 49 50 } 51 52 int main() { 53 test(); 54 }
运行结果:
实验三:
代码:
pets.hpp:
1 #pragma once 2 #include<iostream> 3 #include<string> 4 5 using namespace std; 6 7 class MachinePets { 8 public: 9 MachinePets(const string& name):nickname{name}{} 10 string get_nickname()const { return nickname; } 11 virtual string talk() = 0; 12 13 private: 14 string nickname; 15 }; 16 17 class PetCats :public MachinePets { 18 public: 19 PetCats(const string& name):MachinePets(name) { 20 } 21 22 string talk() { 23 return "miao wu~"; 24 } 25 }; 26 27 class PetDogs :public MachinePets{ 28 public: 29 PetDogs(const string& name) :MachinePets(name) { 30 } 31 32 string talk() { 33 return "wang wang~"; 34 } 35 };
task3.cpp:
1 #include"pets.hpp" 2 #include<iostream> 3 #include<vector> 4 5 void test() { 6 using namespace std; 7 8 vector<MachinePets*>pets; 9 10 pets.push_back(new PetCats("miku")); 11 pets.push_back(new PetDogs("da huang")); 12 13 for (auto& ptr : pets) 14 cout << ptr->get_nickname() << " says " << ptr->talk() << endl; 15 } 16 17 int main() { 18 test(); 19 }
运行结果:
实验四:
film.hpp:
1 #pragma once 2 #include<iostream> 3 #include<string> 4 #include<iomanip> 5 6 using namespace std; 7 8 class Film { 9 public: 10 Film() = default; 11 int getYear()const { return year; } 12 13 friend istream& operator>>(istream& in, Film& f); 14 friend ostream& operator<<(ostream& out, Film& f); 15 private: 16 string name; 17 string director; 18 string area; 19 int year; 20 }; 21 22 istream& operator>>(istream& in, Film &f) { 23 cout << "录入片名:"; in >> f.name; 24 cout << "录入导演:"; in >> f.director; 25 cout << "录入制片国家/地区:"; in >> f.area; 26 cout << "录入上映年份:"; in >> f.year; 27 28 return in; 29 } 30 31 ostream& operator<<(ostream& out, Film &f) { 32 out << left 33 << setw(20) << f.name 34 << setw(20) << f.director 35 << setw(20) << f.area 36 << setw(6) << f.year; 37 38 return out; 39 }
task4.cpp:
1 #include"film.hpp" 2 #include<iostream> 3 #include<string> 4 #include<vector> 5 #include<algorithm> 6 7 bool compare_by_year(const Film &f1,const Film &f2) { 8 return f1.getYear() < f2.getYear(); 9 } 10 11 void test() { 12 using namespace std; 13 14 int n; 15 cout << "输入电影数目:"; 16 cin >> n; 17 18 cout << "录入" << n << "部影片信息" << endl; 19 vector<Film>film_lst; 20 for (int i = 0; i < n; ++i) { 21 Film f; 22 cout << string(20, '-') << "第" << i + 1 << "部影片录入" << string(20, '-') << endl; 23 cin >> f; 24 film_lst.push_back(f); 25 } 26 sort(film_lst.begin(), film_lst.end(), compare_by_year); 27 28 cout << string(20, '=') + "电影信息(按发行年份)" + string(20, '=') << endl; 29 for (auto& f : film_lst) 30 cout << f << endl; 31 32 } 33 34 int main() { 35 test(); 36 }
运行结果:
实验五:
代码:
complex.hpp:
1 #pragma once 2 #include <iostream> 3 4 using namespace std; 5 6 template<typename T> 7 class Complex { 8 public: 9 Complex(const T&r=0,const T&i=0) :real{ r }, imag{ i } {}; 10 Complex(const Complex<T>& c) { 11 this->real = c.real; 12 this->imag = c.imag; 13 } 14 15 Complex operator+=(const Complex<T>& c) { 16 this->real += c.real; 17 this->imag += c.imag; 18 return *this; 19 } 20 21 T get_real() const { return real; } 22 T get_imag() const { return imag; } 23 24 friend Complex operator+(const Complex& c1, const Complex& c2){ return Complex<T>(c1.real + c2.real, c1.imag + c2.imag); } 25 friend bool operator==(const Complex& c1, const Complex& c2){ return c1.real == c2.real && c1.imag == c2.imag; } 26 friend istream& operator>>(istream& in, Complex<T>& c){ 27 in >> c.real >> c.imag; 28 return in; 29 } 30 friend ostream& operator<<(ostream& out, const Complex& c){ 31 out << c.real << (c.imag >= 0 ? "+" : "") << c.imag << "i"; 32 return out; 33 } 34 35 private: 36 T real; 37 T imag; 38 };
task5.cpp:
1 #include "complex.hpp" 2 #include <iostream> 3 4 using std::cin; 5 using std::cout; 6 using std::endl; 7 using std::boolalpha; 8 9 void test1() { 10 Complex<int> c1(2, -5), c2(c1); 11 cout << "c1=" << c1 << endl; 12 cout << "c2=" << c2 << endl; 13 cout << "c1 + c2 = " << c1 + c2 << endl; 14 15 c1 += c2; 16 cout << "c1=" << c1 << endl; 17 cout << boolalpha << (c1 == c2) << endl; 18 } 19 20 void test2() { 21 Complex<double> c1, c2; 22 cout << "Enter c1 and c2:"; 23 cin >> c1 >> c2; 24 cout << "c1=" << c1 << endl; 25 cout << "c2=" << c2 << endl; 26 27 cout << "c1.real=" << c1.get_real() << endl; 28 cout << "c1.imag=" << c1.get_imag() << endl; 29 } 30 31 int main() { 32 cout << "自定义类模板Complex测试1:" << endl; 33 test1(); 34 35 cout << endl; 36 37 cout << "自定义类模板Complex测试2:" << endl; 38 test2(); 39 }
运行结果:
实验六:
代码:
date.h:
1 #pragma once 2 3 class Date { 4 private: 5 int year; 6 int month; 7 int day; 8 int totalDays; 9 10 public: 11 Date(int year, int month, int day); 12 int getYear() const { return year; } 13 int getMonth() const { return month; } 14 int getDay() const { return day; } 15 int getMaxDay() const; 16 bool isLeapYear() const { 17 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0; 18 } 19 void show() const; 20 int operator-(const Date& date) const { 21 return totalDays - date.totalDays; 22 } 23 };
date.cpp:
1 #include "date.h" 2 #include <iostream> 3 #include <cstdlib> 4 using namespace std; 5 6 namespace { 7 const int DAYS_BEFORE_MONTH[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }; 8 } 9 10 Date::Date(int year, int month, int day) : year(year), month(month), day(day) { 11 if (day <= 0 || day > getMaxDay()) { 12 cout << "Invalid date: "; 13 show(); 14 cout << endl; 15 exit(1); 16 } 17 int years = year - 1; 18 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day; 19 if (isLeapYear() && month > 2) totalDays++; 20 } 21 22 int Date::getMaxDay() const { 23 if (isLeapYear() && month == 2) 24 return 29; 25 else return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1]; 26 } 27 28 void Date::show() const { 29 cout << getYear() << "-" << getMonth() << "-" << getDay(); 30 }
accumulator.h:
1 #pragma once 2 #include "date.h" 3 4 class Accumulator { 5 private: 6 Date lastDate; 7 double value; 8 double sum; 9 10 public: 11 Accumulator(const Date& date, double value) : lastDate(date), value(value), sum{ 0 } {} 12 13 double getSum(const Date& date) const { 14 return sum + value * (date - lastDate); 15 } 16 17 void change(const Date& date, double value) { 18 sum = getSum(date); 19 lastDate = date; 20 this->value = value; 21 } 22 23 void reset(const Date& date, double value) { 24 lastDate = date; 25 this->value = value; 26 sum = 0; 27 } 28 };
account.h:
1 #pragma once 2 #include "date.h" 3 #include "accumulator.h" 4 #include <string> 5 using namespace std; 6 7 class Account { 8 private: 9 string id; 10 double balance; 11 static double total; 12 protected: 13 Account(const Date& date, const string& id); 14 void record(const Date& date, double amount, const string& desc); 15 void error(const string& msg) const; 16 public: 17 const string& getId() { return id; } 18 double getBalance() const { return balance; } 19 static double getTotal() { return total; } 20 virtual void deposit(const Date& date, double amount, const string& desc) = 0; 21 virtual void withdraw(const Date& date, double amount, const string& desc) = 0; 22 virtual void settle(const Date& date) = 0; 23 virtual void show() const; 24 }; 25 26 class SavingsAccount : public Account { 27 private: 28 Accumulator acc; 29 double rate; 30 public: 31 SavingsAccount(const Date& date, const string& id, double rate); 32 double getRate() const { return rate; } 33 void deposit(const Date& date, double amount, const string& desc); 34 void withdraw(const Date& date, double amount, const string& desc); 35 void settle(const Date& date); 36 }; 37 38 class CreditAccount : public Account { 39 private: 40 Accumulator acc; 41 double credit; 42 double rate; 43 double fee; 44 double getDebt() const { 45 double balance = getBalance(); 46 return (balance < 0 ? balance : 0); 47 } 48 public: 49 CreditAccount(const Date& date, const string& id, double credit, double rate, double fee); 50 double getCredit() const { return credit; } 51 double getRate() const { return rate; } 52 double getFee() const { return fee; } 53 double getAvailableCredit() const { 54 if (getBalance() < 0) return credit + getBalance(); 55 else return credit; 56 } 57 void deposit(const Date& date, double amount, const string& desc); 58 void withdraw(const Date& date, double amount, const string& desc); 59 void settle(const Date& date); 60 void show() const; 61 };
account.cpp:
1 #include "account.h" 2 #include <cmath> 3 #include<iostream> 4 using namespace std; 5 6 double Account::total = 0; 7 8 Account::Account(const Date& date, const string& id) : id(id), balance(0) { 9 date.show(); 10 cout << "\t#" << id << " created" << endl; 11 } 12 13 void Account::record(const Date& date, double amount, const string& desc) { 14 amount = floor(amount * 100 + 0.5) / 100; 15 balance += amount; 16 total += amount; 17 date.show(); 18 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl; 19 } 20 21 void Account::show() const { 22 cout << id << "\tBalance: " << balance; 23 } 24 25 void Account::error(const string& msg) const { 26 cout << "Error (#" << id << "): " << msg << endl; 27 } 28 29 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) 30 : Account(date, id), rate(rate), acc(date, 0) {} 31 32 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) { 33 record(date, amount, desc); 34 acc.change(date, getBalance()); 35 } 36 37 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) { 38 if (amount > getBalance()) { 39 error("not enough money"); 40 } 41 else { 42 record(date, -amount, desc); 43 acc.change(date, getBalance()); 44 } 45 } 46 47 void SavingsAccount::settle(const Date& date) { 48 double interest = acc.getSum(date) * rate / (date - Date(date.getYear() - 1, 1, 1)); 49 if (interest != 0) record(date, interest, "interest"); 50 acc.reset(date, getBalance()); 51 } 52 53 CreditAccount::CreditAccount(const Date& date, const string& id, double credit, double rate, double fee) 54 : Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) {} 55 56 void CreditAccount::deposit(const Date& date, double amount, const string& desc) { 57 record(date, amount, desc); 58 acc.change(date, getDebt()); 59 } 60 61 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) { 62 if (amount - getBalance() > credit) { 63 error("not enough credit"); 64 } 65 else { 66 record(date, -amount, desc); 67 acc.change(date, getDebt()); 68 } 69 } 70 71 void CreditAccount::settle(const Date& date) { 72 double interest = acc.getSum(date) * rate; 73 if (interest != 0) record(date, interest, "interest"); 74 if (date.getMonth() == 1) record(date, -fee, "annual fee"); 75 acc.reset(date, getDebt()); 76 } 77 78 void CreditAccount::show() const { 79 Account::show(); 80 cout << "\tAvailable credit: " << getAvailableCredit(); 81 }
task6.cpp:
1 #include "account.h" 2 #include<iostream> 3 using namespace std; 4 5 int main() { 6 Date date(2008, 11, 1); 7 SavingsAccount sa1(date, "S3755217", 0.015); 8 SavingsAccount sa2(date, "02342342", 0.015); 9 CreditAccount ca(date, "C5392394", 10000, 0.0005, 50); 10 Account* accounts[] = { &sa1, &sa2, &ca }; 11 const int n = sizeof(accounts) / sizeof(Account*); 12 cout << "(d)deposit (w)withdraw (s)show (c)change day (n)next month (e)exit" << endl; 13 char cmd; 14 do { 15 date.show(); 16 cout << "\tTotal:" << Account::getTotal() << "\tcommand>"; 17 int index, day; 18 double amount; 19 string desc; 20 cin >> cmd; 21 switch (cmd) { 22 case 'd': 23 cin >> index >> amount; 24 getline(cin, desc); 25 accounts[index]->deposit(date, amount, desc); 26 break; 27 case 'w': 28 cin >> index >> amount; 29 getline(cin, desc); 30 accounts[index]->withdraw(date, amount, desc); 31 break; 32 case 's': 33 for (int i = 0; i < n; i++) { 34 cout << "[" << i << "]"; 35 accounts[i]->show(); 36 cout << endl; 37 } 38 break; 39 case 'c': 40 cin >> day; 41 if (day < date.getDay()) { 42 cout << "You cannot specify a previous day"; 43 } 44 else if (day > date.getMaxDay()) 45 cout << "Invalid day"; 46 else date = Date(date.getYear(), date.getMonth(), day); 47 break; 48 case 'n': 49 if (date.getMonth() == 12) 50 date = Date(date.getYear() + 1, 1, 1); 51 else date = Date(date.getYear(), date.getMonth() + 1, 1); 52 for (int i = 0; i < n; i++) { 53 accounts[i]->settle(date); 54 } 55 break; 56 } 57 } while (cmd != 'e'); 58 return 0; 59 }
运行结果: