实验五 c++
任务三：
Pet.hpp:
#pragma once
#include <iostream>
#include <string>
using std::cout;
using std::endl;
using std::string;
class MachinePets {
public:
MachinePets(const string& s);
public:
virtual string talk() const = 0;
string get_nickname() const {
return nickname;
}
protected:
string nickname;
};
MachinePets::MachinePets(const string& s):nickname(s){}
class PetCats :public MachinePets {
public:
PetCats(const string& s):MachinePets(s) {}
public:
string talk() const override {
return "Meow";
}
};
class PetDogs :public MachinePets {
public:
PetDogs(const string& s):MachinePets(s) {}
public:
string talk() const override {
return "Woof";
}
};
task3.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();
}
实验结果截图：
任务四：
film.hpp:
#pragma once
#include<string>
#include<iostream>
#include<iomanip>
#include <algorithm>
using namespace std;
class Film
{
public:
int get_year() const {
return year;
}
friend ostream& operator<<(ostream& os, const Film& film);
friend istream& operator>>(istream& is, Film& film);
private:
string name;
string director;
string area;
int year;
};
ostream& operator<<(ostream& out, const Film& film)
{
out << setw(10) << left << film.name << setw(10) << left << film.director << setw(10) << left << film.area << setw(10) << left << film.year;
return out;
}
istream& operator>>(istream& in, Film& film)
{
cout << "录入片名：";
in >> film.name;
cout <<"录入导演：";
in>>film.director;
cout << "录入地区：";
in>>film.area;
cout << "录入年份：";
in>>film.year;
return in;
}
bool compare_by_year(const Film& f1, const Film& f2) {
return f1.get_year() < f2.get_year();
}
task4.cpp;
#include "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);
}
// 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 (auto& f : film_lst)
cout << f << endl;
}
int main() {
test();
}
实验结果截图:
任务五：
Complex.hpp:
#pragma once
#include <iostream>
#include <cmath>
template <typename T>
class Complex {
private:
T real; // 实部
T imag; // 虚部
public:
// 构造函数
Complex(T r = 0, T i = 0) : real(r), imag(i) {}
Complex& operator+=(const Complex& c) {
real += c.real;
imag += c.imag;
return *this; // 返回自身引用
}
// 获取实部
T get_real() const {
return real;
}
// 获取虚部
T get_imag() const {
return imag;
}
// 重载加法运算符
Complex operator+(const Complex& other) const {
return Complex(real + other.real, imag + other.imag);
}
bool operator==(const Complex& other) const {
return (real == other.real) && (imag == other.imag);
}
friend std::istream& operator>>(std::istream& in, Complex& c) {
in >> c.real >> c.imag;
return in;
}
// 重载输出流运算符
friend std::ostream& operator<<(std::ostream& os, const Complex& c) {
os << c.real << " + " << c.imag << "i";
return os;
}
};
task.cpp:
#include "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();
}
实验结果截图:
任务六:
date.h:
//date.h
#ifndef DATE_H
#define DATE_H
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;
}
};
#endif // DATE_H
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:
#ifndef ACCUMULATOR_H
#define ACCUMULATOR_H
#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;
}
};
#endif
account.h
#ifndef ACCOUNT_H
#define ACCOUNT_H
#include"date.h"
#include"accumulator.h"
#include<string>
class Account {
private:
std::string id;
double balance;
static double total;
protected:
Account(const Date& date, const std::string& id);
void record(const Date& date, double amount, const std::string& desc);
void error(const std::string& msg)const;
public:
const std::string &getId()const {return id;}
double getBalance()const { return balance; }
static double getTotal() { return total; }
virtual void deposit(const Date& date, double amount, const std::string& desc) = 0;
virtual void withdraw(const Date& date, double amount, const std::string& desc) = 0;
virtual void settle(const Date& date) = 0;
virtual void show()const;
};
class SavingsAccount : public Account {//储账户类
private:
Accumulator acc; //辅助计算利息的累加器
double rate; //存款的年利率
public:
//构造函数
SavingsAccount(const Date& date, const std::string& id, double rate);
double getRate() const { return rate; }
//存入现金
void deposit(const Date& date, double amount, const std::string& desc);
//取出现金
void withdraw(const Date& date, double amount, const std::string& desc);
void settle(const Date& date); //结算利息，每年1月1日调用一次该函数
};
class CreditAccount :public Account {//信用账户类
private:
Accumulator acc; //辅助计算利息的累加器
double credit; //信用额度
double rate; //欠款的日利率
double fee; //信用卡年费
double getDebt() const { //获得欠款额
double balance = getBalance();
return (balance < 0 ? balance : 0);
}
public:
//构造函数
CreditAccount(const Date& date, const std::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 {
//获得可用信用
if (getBalance() < 0)
return credit + getBalance();
else
return credit;
}
//存入现金
void deposit(const Date& date, double amount, const std::string& desc);
//取出现金
void withdraw(const Date& date, double amount, const std::string& desc);
void settle(const Date& date); //结算利息和年费，每月1日调用一次该函数
void show() const;
};
#endif // _ACCOUNT_H_
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) {
if (date.getMonth() == 1) {
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();
}
8_8.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':
// 查询各账户信息
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;
}
实验结果截图:
经过改进,对账户的各种操作都可以通过基类的指针来调用，增加了程序的灵活性。
利用运算符重载后的代码更具可读性。
