实验五
任务3
1 #include<iostream> 2 #include<stdlib.h> 3 #include<string> 4 using namespace std; 5 class MachinePets 6 { 7 private: 8 string nickname; 9 public: 10 MachinePets(const string s) :nickname{ s } {} 11 string get_nickname() const { return nickname; } 12 virtual string talk() = 0; 13 }; 14 class PetCats :public MachinePets 15 { 16 public: 17 PetCats(const string s) :MachinePets{ s } {} 18 string talk() 19 { 20 return "miao wu~"; 21 } 22 23 24 }; 25 class PetDogs:public MachinePets 26 { 27 public: 28 PetDogs(const string s) :MachinePets{ s } {} 29 string talk() 30 { 31 return "wang wang~"; 32 } 33 system("pause"); 34 };
1 #include <iostream> 2 #include"machinepets.hpp" 3 4 void play(MachinePets &obj) { 5 std::cout << obj.get_nickname() << " says " << obj.talk() << std::endl; 6 } 7 8 void test() { 9 PetCats cat("miku"); 10 PetDogs dog("da huang"); 11 12 play( cat ); 13 play( dog ); 14 } 15 16 int main() { 17 test(); 18 }

任务4
#include<iostream> #include<stdlib.h> #include<vector> #include<string> using namespace std; class Person { public: Person(); Person(string n, string t,string e=0); Person(const Person& p); void update_telephone(); void update_email(); friend istream& operator>>(istream& is, Person& p); friend ostream& operator<<(ostream& os, Person& p); friend bool operator==(const Person& a, const Person& b); private: string name; string telephone; string email; }; Person::Person() {} Person::Person(string n, string t, string e) { name = n; telephone = t; email = e; } Person::Person(const Person& p) { this->name = p.name; this->telephone = p.telephone; this->email = p.email; } void Person::update_telephone() { string m = "19218132577"; cin >> m; cout << "输入电话号码:" <<m<< endl; cout << "电话号码已更新" << endl; } void Person::update_email() { string n = "gmma@cmu.edu.cn"; cin >> n; cout << "输入email地址:" <<n<< endl; cout << "email地址已更新" << endl; } istream& operator>>(istream& is, Person& p) { is >> p.name >> p.telephone >> p.email; return is; } ostream& operator<<(ostream& os, Person& p) { os << p.name << p.telephone << p.email; return os; } bool operator==(const Person& a, const Person& b) { return(a.name == b.name); system("pause"); }
1 #include <iostream> 2 #include <vector> 3 #include "Person.hpp" 4 5 void test() { 6 using namespace std; 7 8 vector<Person> phone_book; 9 Person p; 10 11 cout << "输入一组联系人的联系方式,E直至按下Ctrl+Z终止\n"; 12 while(cin >> p) 13 phone_book.push_back(p); 14 15 cout << "\n更新phone_book中索引为0的联系人的手机号、邮箱:\n"; 16 phone_book.at(0).update_telephone(); 17 phone_book.at(0).update_email(); 18 19 cout << "\n测试两个联系人是否是同一个:\n"; 20 cout << boolalpha << (phone_book.at(0) == phone_book.at(1)) << endl; 21 } 22 23 int main() { 24 test(); 25 }

任务5
1 class Date { 2 private: 3 int year; 4 int month; 5 int day; 6 int totalDays; 7 public: 8 Date(int year, int month, int day); 9 int getYear() const { return year; } 10 int getMonth() const { return month; } 11 int getDay() const { return day; } 12 int getMaxDay() const; 13 bool isLeapYear() const { 14 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0; 15 } 16 void show() const; 17 int operator-(const Date& date) const { 18 return totalDays - date.totalDays; 19 } 20 };
1 #include"date.h" 2 #include<iostream> 3 #include<cstdlib> 4 5 using namespace std; 6 7 namespace 8 { 9 const int DAYS_BEFORE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 }; 10 } 11 12 Date::Date(int year, int month, int day) :year(year), month(month), day(day) 13 { 14 if (day <= 0 || day > getMaxDay()) 15 { 16 cout << "INvalid date:"; 17 show(); 18 cout << endl; 19 exit(1); 20 } 21 int years = year - 1; 22 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day; 23 if (isLeapYear() && month > 2) totalDays++; 24 } 25 26 int Date::getMaxDay() const 27 { 28 if (isLeapYear() && month == 2) 29 return 29; 30 else 31 return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1]; 32 } 33 34 void Date::show() const 35 { 36 cout << getYear() << "-" << getMonth() << "-" << getDay(); 37 }
1 #include"date.h" 2 class Accumulator 3 { 4 private: 5 Date lastDate; 6 double value; 7 double sum; 8 public: 9 Accumulator(const Date& date, double value) :lastDate(date), value(value), sum(0) {} 10 11 double getSum(const Date& date) const { 12 return sum + value * (date - lastDate); 13 } 14 15 void change(const Date& date, double value) { 16 sum = getSum(date); 17 lastDate = date; this->value = value; sum = 0; 18 } 19 20 void reset(const Date& date, double value) { 21 lastDate = date; this->value = value; 22 } 23 };
1 #include"date.h" 2 #include"accumulator.h" 3 #include<string> 4 5 class Account 6 { 7 private: 8 std::string id; 9 double balance; 10 static double total; 11 protected: 12 Account(const Date& date, const std::string& id); 13 void record(const Date& date, double amount, const std::string& desc); 14 void error(const std::string& msg) const; 15 public: 16 const std::string& getId() const { return id; } 17 double getBalance() const { return balance; } 18 static double getToal() { return total; } 19 virtual void deposit(const Date& date, double amount, const std::string& desc) = 0; 20 virtual void withdraw(const Date& date, double amount, const std::string& desc) = 0; 21 virtual void settle(const Date& date); 22 virtual void show() const; 23 }; 24 25 class SavingsAccount :public Account 26 { 27 private: 28 Accumulator acc; 29 double rate; 30 public: 31 SavingsAccount(const Date& date, const std::string& id, double rate); 32 double getRate() const { return rate; } 33 void deposit(const Date& date, double amount, const std::string& desc); 34 void withdraw(const Date& date, double amount, const std::string& desc); 35 void settle(const Date& date); 36 }; 37 38 class CreditAccount :public Account 39 { 40 private: 41 Accumulator acc; 42 double credit; 43 double rate; 44 double fee; 45 double getDebt() const 46 { 47 double balance = getBalance(); 48 return(balance < 0 ? balance : 0); 49 } 50 public: 51 CreditAccount(const Date& date, const std::string& id, double credit, double rate, double fee); 52 double getCredit() const { return credit; } 53 double getRate() const { return rate; } 54 double getFee() const { return fee; } 55 double getAvailableCredit() const { 56 if (getBalance() < 0) 57 return credit + getBalance(); 58 else 59 return credit; 60 } 61 void deposit(const Date& date, double amount, const std::string& desc); 62 void withdraw(const Date& date, double amount, const std::string& desc); 63 void settle(const Date& date); 64 void show() const; 65 };
1 #include"account.h" 2 #include<cmath> 3 #include<iostream> 4 5 using namespace std; 6 7 double Account::total = 0; 8 9 Account::Account(const Date& date, const std::string& id) :id(id), balance(0) 10 { 11 date.show(); cout << "\t#" << id << "created" << endl; 12 } 13 void Account::record(const Date& date, double amount, const string& desc) 14 { 15 amount = floor(amount * 100 + 0.5) / 100; 16 balance += amount; total += amount; 17 date.show(); 18 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl; 19 } 20 void Account::show() const { cout << id << "\tBalance:" << balance; } 21 void Account::error(const string& msg) const 22 { 23 cout << "Error(#" << id << "):" << msg << endl; 24 } 25 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :Account(date, id), rate(rate), acc(date, 0) { 26 } 27 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) 28 { 29 record(date, amount, desc); 30 acc.change(date, getBalance()); 31 } 32 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) 33 { 34 if (amount > getBalance()) 35 { 36 error("not enough money"); 37 } 38 else 39 { 40 record(date, -amount, desc); 41 acc.change(date, getBalance()); 42 } 43 } 44 void SavingsAccount::settle(const Date& date) 45 { 46 if (date.getMonth() == 1) 47 { 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) :Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) { 54 } 55 void CreditAccount::deposit(const Date& date, double amount, const string& desc) 56 { 57 record(date, amount, desc); 58 acc.change(date, getDebt()); 59 } 60 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) 61 { 62 if (amount - getBalance() > credit) 63 { 64 error("not enough credit"); 65 } 66 else 67 { 68 record(date, -amount, desc); 69 acc.change(date, getDebt()); 70 } 71 } 72 void CreditAccount::settle(const Date& date) 73 { 74 double interest = acc.getSum(date) * rate; 75 if (interest != 0) record(date, interest, "interest"); 76 if (date.getMonth() == 1) record(date, -fee, "annual fee"); 77 acc.reset(date, getDebt()); 78 } 79 void CreditAccount::show() const 80 { 81 Account::show(); 82 cout << "\tAvailable credit:" << getAvailableCredit(); 83 }
1 #include"account.h" 2 #include<iostream> 3 using namespace std; 4 int main() 5 { 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::getToal() << "\tcommand"; 17 int index, day; 18 double amount; string desc; 19 cin >> cmd; 20 switch (cmd) 21 { 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 { 35 cout << "[" << i << "]"; 36 accounts[i]->show(); 37 cout << endl; 38 } 39 break; 40 case'c': 41 cin >> day; 42 if (day << date.getDay()) 43 cout << "You cannot specify a previous day"; 44 else if (day > date.getMaxDay()) 45 cout << "Invalid day"; 46 else 47 date = Date(date.getYear(), date.getMonth(), day); 48 break; 49 case'n': 50 if (date.getMonth() == 12) 51 date = Date(date.getYear() + 1, 1, 1); 52 else 53 date = Date(date.getYear(), date.getMonth() + 1, 1); 54 for (int i = 0; i < n; i++) 55 accounts[i]->settle(date); 56 break; 57 } 58 } while (cmd != 'e'); 59 return 0; 60 }

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