实验5 继承和多态

任务三：

pets.hpp

 1 #include <iostream>
 2 #include <string>
 3 
 4 using std::string;
 5 using std::cout;
 6 using std::endl;
 7 
 8 class MachinePets {
 9 public:
10     MachinePets(const string& name): nickname{name} {}
11     string get_nickname() {
12         return nickname;
13     }
14     virtual string talk() = 0;
15 private:
16     string nickname;
17 };
18 
19 class PetCats: public MachinePets {
20 public:
21     PetCats(const string& name): MachinePets{name} {}  
22     string talk() override {
23         return "miao wu~";
24     }
25 };
26 
27 class PetDogs: public MachinePets {
28 public:
29     PetDogs(const string& name): MachinePets{name} {}
30     string talk() override {
31         return "wang wang~";
32     }
33 };
pets.hpp

task3.cpp

 1 #include <iostream>
 2 #include <string>
 3 
 4 using std::string;
 5 using std::cout;
 6 using std::endl;
 7 
 8 class MachinePets {
 9 public:
10     MachinePets(const string& name): nickname{name} {}
11     string get_nickname() {
12         return nickname;
13     }
14     virtual string talk() = 0;
15 private:
16     string nickname;
17 };
18 
19 class PetCats: public MachinePets {
20 public:
21     PetCats(const string& name): MachinePets{name} {}  
22     string talk() override {
23         return "miao wu~";
24     }
25 };
26 
27 class PetDogs: public MachinePets {
28 public:
29     PetDogs(const string& name): MachinePets{name} {}
30     string talk() override {
31         return "wang wang~";
32     }
33 };
task3.cpp

运行结果：

 

任务四：

film.hpp

 1 #pragma once
 2 
 3 #include <iostream>
 4 #include <string>
 5 #include <iomanip>
 6 
 7 using std::string;
 8 using std::cout;
 9 using std::endl;
10 using std::istream;
11 using std::ostream;
12 using std::left;
13 using std::setw;
14 
15 
16 class Film {
17 public:
18     Film(string name = "",string director = "",string area = "",int year = 0) {
19         this->name = name;
20         this->director = director;
21         this->area = area;
22         this->year = year;
23     }    
24     int get_year() const {
25         return year;
26     } 
27     
28     friend istream& operator>>(istream &in,Film &f) {
29         cout << "录入片名：";
30         in >> f.name; 
31         cout << "录入导演：";
32         in >> f.director;
33         cout << "录入制片国家/地区：";
34         in >> f.area;
35         cout << "录入上映年份：";
36         in >> f.year;
37         
38         return in;
39     }
40     
41     friend ostream& operator<<(ostream &out,const Film &f) {
42         out << left;
43         out << setw(20) << f.name
44             << setw(20) << f.director
45             << setw(20) << f.area
46             << setw(20) << f.year;
47         
48         return out;
49     }
50     
51     
52 private:
53     string name,director,area;
54     int year;
55 }; 
56 
57 bool compare_by_year(const Film &f1,const Film &f2) {
58     return f1.get_year() < f2.get_year();
59 }
film.hpp

task4.cpp

 1 #include "film.hpp"
 2 #include <iostream>
 3 #include <string>
 4 #include <vector>
 5 #include <algorithm>
 6 
 7 void test() {
 8     using namespace std;
 9     
10     int n;
11     cout << "输入电影数目: ";
12     cin >> n;
13 
14     cout << "录入" << n << "部影片信息" << endl;
15     vector<Film> film_lst;
16     for(int i = 0; i < n; ++i) {
17         Film f;
18         cout << string(20, '-') << "第" << i+1 << "部影片录入" << string(20, '-') << endl;
19         cin >> f;
20         film_lst.push_back(f);
21     }
22 
23     // 按发行年份升序排序
24     sort(film_lst.begin(), film_lst.end(), compare_by_year);
25 
26     cout << string(20, '=') + "电影信息(按发行年份)" +  string(20, '=')<< endl;
27     for(auto &f: film_lst)
28         cout << f << endl;
29 }
30 
31 int main() {
32     test();
33 }
task4.cpp

运行结果：

 

任务五：

Complex.hpp

 1 #pragma once
 2 
 3 #include <iostream>
 4 
 5 using std::cout;
 6 using std::endl;
 7 using std::istream;
 8 using std::ostream;
 9 
10 template<typename T>
11 class Complex {
12 public:
13     Complex(T real = 0,T imag = 0): r{real},i{imag} {}
14     Complex operator+=(const Complex &c) {
15         r += c.r;
16         i += c.i;
17         return *this;
18     }
19     double get_real() {
20         return r;
21     }
22     double get_imag() {
23         return i;
24     }
25     
26     friend bool operator==(const Complex &c1,const Complex &c2) {
27         if( c1.r == c2.r || c1.i == c2.i )
28         return true;
29         else
30         return false;
31     }
32     
33     friend Complex operator+(const Complex &c1,const Complex &c2) {
34         return Complex( c1.r+c2.r,c1.i+c2.i );
35     }
36     
37     friend istream& operator>>(istream& in,Complex &c) {
38         in >> c.r >> c.i;
39         return in;
40     }
41     friend ostream& operator<<(ostream& out,const Complex &c) {
42         if( c.i < 0 )
43             out << c.r << " - " << -c.i << "i";
44         else
45             cout << c.r << " + " << c.i << "i"; 
46         return out; 
47     }
48 private:
49     T r,i;
50 };
Complex.hpp

task5.hpp

 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 
12     cout << "c1 = " << c1 << endl;
13     cout << "c2 = " << c2 << endl;
14     cout << "c1 + c2 = " << c1 + c2 << endl;
15     
16     c1 += c2;
17     cout << "c1 = " << c1 << endl;
18     cout << boolalpha << (c1 == c2) << endl;
19 }
20 
21 void test2() {
22     Complex<double> c1, c2;
23     cout << "Enter c1 and c2: ";
24     cin >> c1 >> c2;
25     cout << "c1 = " << c1 << endl;
26     cout << "c2 = " << c2 << endl;
27 
28     cout << "c1.real = " << c1.get_real() << endl;
29     cout << "c1.imag = " << c1.get_imag() << endl;
30 }
31 
32 int main() {
33     cout << "自定义类模板Complex测试1: " << endl;
34     test1();
35 
36     cout << endl;
37 
38     cout << "自定义类模板Complex测试2: " << endl;
39     test2();
40 }
task5.cpp

运行结果：

 

任务六：

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.h

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 }
date.cpp

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 };
accumulator.h

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.h

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 }
account.cpp

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 }
task6.cpp

运行结果：

 

改进：

1.将基类 Account 部分特定函数设置为虚函数和纯虚函数，使得可以通过基类的指针来调用对账户的各种操作，因此，可以把各账户对象的指针都放在一个数组中，通过数组索引就能够对几个账户对象进行操作；

2.进行了运算符重载；

 

posted @ 2024-12-07 14:03  F&WJ  阅读(15)  评论(0)    收藏  举报