类和对象_基础编程2

任务三：

#ifndef T_HPP
#define T_HPP

#include <iostream>
#include <cmath>

class Complex {
private:
    double real; // 实部
    double imag; // 虚部
public:
    Complex();
    Complex(double r);
    Complex(double r, double i);
    Complex(const Complex& c);
    double get_imag() const;
    void show() const;
    friend double abs(const Complex& c);
    friend bool is_equal(const Complex& c1, const Complex& c2);
    friend Complex add(const Complex& c1, const Complex& c2);
    void add(const Complex& c);
    Complex& operator+=(const Complex& c);
};

#endif

#include "t.hpp"

Complex::Complex() : real(0), imag(0) {}

Complex::Complex(double r) : real(r), imag(0) {}

Complex::Complex(double r, double i) : real(r), imag(i) {}

Complex::Complex(const Complex& c) : real(c.real), imag(c.imag) {}

double Complex::get_imag() const {
    return imag;
}

void Complex::show() const {
    std::cout << real;
    if (imag >= 0) {
        std::cout << " + " << imag << "i";
    } else {
        std::cout << " - " << -imag << "i";
    }
}

double abs(const Complex& c) {
    return std::sqrt(c.real * c.real + c.imag * c.imag);
}

bool is_equal(const Complex& c1, const Complex& c2) {
    return c1.real == c2.real && c1.imag == c2.imag;
}

Complex add(const Complex& c1, const Complex& c2) {
    Complex result;
    result.real = c1.real + c2.real;
    result.imag = c1.imag + c2.imag;
    return result;
}

void Complex::add(const Complex& c) {
    real += c.real;
    imag += c.imag;
}

Complex& Complex::operator+=(const Complex& c) {
    add(c);
    return *this;
}

#include "t.hpp"

void test() {
    Complex c1(3, -4);
    const Complex c2(4.5);
    Complex c3(c1);
    std::cout << "c1 = ";
    c1.show();
    std::cout << std::endl;
    std::cout << "c2 = ";
    c2.show();
    std::cout << std::endl;
    std::cout << "c2.imag = " << c2.get_imag() << std::endl;
    std::cout << "c3 = ";
    c3.show();
    std::cout << std::endl;
    std::cout << "abs(c1) = ";
    std::cout << abs(c1) << std::endl;
    std::cout << std::boolalpha;
    std::cout << "c1 == c3 : " << is_equal(c1, c3) << std::endl;
    std::cout << "c1 == c2 : " << is_equal(c1, c2) << std::endl;
    Complex c4;
    c4 = add(c1, c2);
    std::cout << "c4 = c1 + c2 = ";
    c4.show();
    std::cout << std::endl;
    c1 += c2;
    std::cout << "c1 += c2, " << "c1 = ";
    c1.show();
    std::cout << std::endl;
}

int main() {
    test();
    return 0;
}

运行测试截图：

 

任务四：

 

程序源码：

#include <iostream>
#include <string>

class User {
private:
    std::string name;
    std::string passwd;
    std::string email;
    static int n;

public:
    User(const std::string& name, const std::string& passwd, const std::string& email) :
        name(name), passwd(passwd), email(email) {
        ++n;
    }

    User(const std::string& name) : name(name) {
        ++n;
    }

    void set_email() {
        std::string new_email;
        std::cout << "Enter email address: ";
        std::cin >> new_email;
        std::cout << "Email is set successfully..." << std::endl;
        email = new_email;
    }

    void change_passwd() {
        std::string old_passwd;
        std::string new_passwd1;

        int try_count = 0;
        while (try_count < 3) {
            std::cout << "Enter old password: ";
            std::cin >> old_passwd;
            if (old_passwd == passwd) {
                break;
            } else {
                std::cout << "Password input error. Please re-enter again: " << std::endl;
                ++try_count;
            }
        }
        if (try_count == 3) {
            std::cout << "Password input error. Please try after a while." << std::endl;
            return;
        }
        while (true) {
            std::cout << "Enter new password: ";
            std::cin >> new_passwd1;
            std::cout << "new passwd is set successfully..." << std::endl;
            passwd = new_passwd1;
            break;
        }
    }

    void print_info() const {
        std::cout << "name: " << name << std::endl;
        std::cout << "passwd: ";
        for (size_t i = 0; i < passwd.size(); ++i) {
            std::cout << "*";
        }
        std::cout << std::endl;
        std::cout << "email: " << email << std::endl;
    }

    static void print_n() {
        std::cout << "there are " << n << " users." << std::endl;
    }
};

int User::n = 0;

#include "User.hpp"
#include <iostream>
// 测试User类
void test() {
using std::cout;
using std::endl;
cout << "testing 1......\n";
User user1("Jonny", "92197", "xyz@hotmail.com");
user1.print_info();
cout << endl
<< "testing 2......\n\n";
User user2("Leonard");
user2.change_passwd();
user2.set_email();
user2.print_info();
cout << endl;
User::print_n();
}
int main() {
test();
}

运行测试结果截图：

 

任务5：

程序源码：

#ifndef __ACCOUNT_H__
#define __ACCOUNT_H__
class SavingsAccount {//储蓄账户类
private:
    int id;
    double balance;
    double rate;
    int lastDate;
    double accumulation;
    static double total;
    void record(int date, double amount);
    double accumulate(int date) const {
        return accumulation+balance*(date-lastDate);
    }
public:
    SavingsAccount(int date, int id, double rate);
    int getId() const {return id;}
    double getBalance() const {return balance;}
    double getRate() const {return rate;}
    static double getTotal() {return total;}
    void deposit(int date, double amount);
    void withdraw(int date, double amount);
    void settle(int date);
    void show() const;
};
#endif

#include"account.h"
#include<cmath>
#include<iostream>
using namespace std;

double SavingsAccount::total = 0;
SavingsAccount::SavingsAccount(int date, int id, double rate)
:id(id),balance(0),rate(rate),lastDate(date),accumulation(0){
    cout << date << "\t#" << id << " is created" << endl;
}
void SavingsAccount::record(int date, double amount) {
    accumulation=accumulate(date);
    lastDate = date;
    amount = floor(amount * 100 + 0.5) / 100;
    balance += amount;
    total += amount;
    cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
}
void SavingsAccount::deposit(int date, double amount) {
    record(date, amount);
}
void SavingsAccount::withdraw(int date, double amount) {
    if ( amount > getBalance())
    cout << "Error: not enough money" << endl;
    else
    record(date, - amount);
}
void SavingsAccount::settle(int date) {
    double interest = accumulate(date) * rate / 365;
    if (interest != 0)
    record(date, interest);
    accumulation = 0;
}
void SavingsAccount::show() const {
     cout << "#" << id << "\tBalance: " << balance;
}

#include "account.h"
#include <iostream>
using namespace std;
int main() {
    SavingsAccount sa0(1, 21325302, 0.015);
    SavingsAccount sa1(1, 58320212, 0.015);
    sa0.deposit(5, 5000) ;
    sa1.deposit(25, 10000);
    sa0.deposit(45, 5500);
    sa1.withdraw(60, 4000);
    
    sa0.settle(90);
    sa1.settle(90);
    
    sa0.show();cout << endl;
    sa1.show();cout << endl;
    cout << "Total:" << SavingsAccount::getTotal() << endl;
    return 0;
}

运行测试结果截图：