实验3 类和对象_基础编程2

任务一

task1.cpp

button.hpp
#pragma once
#include <iostream>
#include <string>
using std::string;
using std::cout;
// 按钮类
class Button {
public:
    Button(const string &text);
    string get_label() const;
void click();
private:
    string label;
};
Button::Button(const string &text): label{text} {}
inline string Button::get_label() const {
    return label;
}
void Button::click() {
    cout << "Button '" << label << "' clicked\n";
}


window.hpp
#pragma once
#include "button.hpp"
#include <vector>
#include <iostream>
using std::vector;
using std::cout;
using std::endl;
// 窗口类
class Window{
public:
    Window(const string &win_title);
void display() const;
void close();
void add_button(const string &label);
private:
    string title;
    vector<Button> buttons;
};
Window::Window(const string &win_title): title{win_title} {
    buttons.push_back(Button("close"));
}
inline void Window::display() const {
    string s(40, '*');
    cout << s << endl;
    cout << "window title: " << title << endl;
    cout << "It has " << buttons.size() << " buttons: " << endl;
    for(const auto &i: buttons)
        cout << i.get_label() << " button" << endl;
        cout << s << endl;
}
void Window::close() {
    cout << "close window '" << title << "'" << endl;
    buttons.at(0).click();
}
void Window::add_button(const string &label) {buttons.push_back(Button(label));
}


task1.cpp
#include "window.hpp"
#include <iostream>
using std::cout;
using std::cin;
void test() {
    Window w1("new window");
    w1.add_button("maximize");
    w1.display();
    w1.close();
}
int main() {
    cout << "用组合类模拟简单GUI:\n";
    test();
}

 问题1：2个类。使用了vector，iostream，string类。window和button之间存在组合关系。

问题2：不适合。const对象不可修改，inline函数是用于提高效率，代码编写时未用到说明此处不适用或者用了不起作用，尤其是const修饰时可能会导致构造函数失去作用。

问题3：输出40个“*”来分割界面。

任务二

task2.cpp

#include <iostream>
#include <vector>

using namespace std;

void output1(const vector<int> &v) {
    for(auto &i: v)
        cout << i << ", ";
    cout << "\b\b \n";
}

void output2(const vector<vector<int>> v) {
    for(auto &i: v) {
        for(auto &j: i)
            cout << j << ", ";
        cout << "\b\b \n";
    }
}

void test1() {
    vector<int> v1(5, 42);
    const vector<int> v2(v1);

    v1.at(0) = -999;
    cout << "v1: ";  output1(v1);
    cout << "v2: ";  output1(v2);
    cout << "v1.at(0) = " << v1.at(0) << endl;
    cout << "v2.at(0) = " << v2.at(0) << endl;
}

void test2() {
    vector<vector<int>> v1{{1, 2, 3}, {4, 5, 6, 7}};
    const vector<vector<int>> v2(v1);

    v1.at(0).push_back(-999);
    cout << "v1: \n";  output2(v1);
    cout << "v2: \n";  output2(v2);

    vector<int> t1 = v1.at(0);
    cout << t1.at(t1.size()-1) << endl;
    
    const vector<int> t2 = v2.at(0);
    cout << t2.at(t2.size()-1) << endl;
}

int main() {
    cout << "测试1:\n";
    test1();

    cout << "\n测试2:\n";
    test2();
}

问题1：用42初始化5个int类型的元素并存入v2。将v1复制给v2。将v1索引为0的元素赋值为-999。

问题2：用两个子向量初始化v1。将v1拷贝给v2。将v1索引为0的元素赋值为-999。

问题3：将v1的第一个元素赋值给t1。输出t1的最后一个元素。将v2的第一个元素赋值给t2。输出t2的最后一个元素。

问题4：深复制。不需要。

任务三

task3.cpp

vectorlnt.hpp
#pragma once

#include <iostream>
#include <cassert>

using std::cout;
using std::endl;

// 动态int数组对象类
class vectorInt{
public:
    vectorInt(int n);
    vectorInt(int n, int value);
    vectorInt(const vectorInt &vi);
    ~vectorInt();

    int& at(int index);
    const int& at(int index) const;

    vectorInt& assign(const vectorInt &v);
    int get_size() const;

private:
    int size;
    int *ptr;       // ptr指向包含size个int的数组
};

vectorInt::vectorInt(int n): size{n}, ptr{new int[size]} {
}

vectorInt::vectorInt(int n, int value): size{n}, ptr{new int[size]} {
    for(auto i = 0; i < size; ++i)
        ptr[i] = value;
}

vectorInt::vectorInt(const vectorInt &vi): size{vi.size}, ptr{new int[size]} {
    for(auto i = 0; i < size; ++i)
        ptr[i] = vi.ptr[i];
}

vectorInt::~vectorInt() {
    delete [] ptr;
}

const int& vectorInt::at(int index) const {
    assert(index >= 0 && index < size);

    return ptr[index];
}

int& vectorInt::at(int index) {
    assert(index >= 0 && index < size);

    return ptr[index];
}

vectorInt& vectorInt::assign(const vectorInt &v) {  
    delete[] ptr;       // 释放对象中ptr原来指向的资源

    size = v.size;
    ptr = new int[size];

    for(int i = 0; i < size; ++i)
        ptr[i] = v.ptr[i];

    return *this;
}

int vectorInt::get_size() const {
    return size;
}


task3.cpp
#include "vectorInt.hpp"
#include <iostream>

using std::cin;
using std::cout;

void output(const vectorInt &vi) {
    for(auto i = 0; i < vi.get_size(); ++i)
        cout << vi.at(i) << ", ";
    cout << "\b\b \n";
}


void test1() {
    int n;
    cout << "Enter n: ";
    cin >> n;

    vectorInt x1(n);
    for(auto i = 0; i < n; ++i)
        x1.at(i) = i*i;
    cout << "x1: ";  output(x1);

    vectorInt x2(n, 42);
    vectorInt x3(x2);
    x2.at(0) = -999;
    cout << "x2: ";  output(x2);
    cout << "x3: ";  output(x3);
}

void test2() {
    const vectorInt  x(5, 42);
    vectorInt y(10, 0);

    cout << "y: ";  output(y);
    y.assign(x);
    cout << "y: ";  output(y);
    
    cout << "x.at(0) = " << x.at(0) << endl;
    cout << "y.at(0) = " << y.at(0) << endl;
}

int main() {
    cout << "测试1: \n";
    test1();

    cout << "\n测试2: \n";
    test2();
}

问题1：深复制。

问题2：有。可能会导致函数出错。

问题3：不可以。可能会导致函数出错。

任务四

task4.cpp

matrix.hpp:
#pragma once
#include <iostream>
#include <cassert>
using std::cout;
using std::endl;
// 类Matrix的声明
class Matrix {
public:
    Matrix(int n, int m);
    Matrix(int n);
    Matrix(const Matrix& x);
    ~Matrix();
    void set(const double* pvalue);
    void clear();
    const double& at(int i, int j) const;   
    double& at(int i, int j);
    int get_lines() const;
    int get_cols() const;
    void display() const;
private:
    int lines;
    int cols;
    double* ptr;
}; 
int value;
Matrix::Matrix(int n, int m) {
    lines = n;
    cols = m;
    ptr = new double[n * m];
}
Matrix::Matrix(int n) {
    lines = n;
    cols = n;
    ptr = new double[n * n];
}
Matrix::Matrix(const Matrix& x) {
    ptr = new double[x.lines * x.cols];
    for (int i = 0; i < x.lines * x.cols; i++) {
        ptr[i] = x.ptr[i];
    }
}
Matrix::~Matrix() {
    delete[] ptr;
}
void Matrix::set(const double* pvalue) {
    for (int i = 0; i < lines * cols; i++)
        ptr[i] = pvalue[i];
}
void Matrix::clear() {
    for (int i = 0; i < lines * cols; i++)
        ptr[i] = 0;
}
const double& Matrix::at(int i, int j) const {
    assert(i >= 0 && i < lines && j >= 0 && j < cols);
    return ptr[i * cols + j];
}

double& Matrix::at(int i, int j) {
    assert(i >= 0 && i < lines && j >= 0 && j < cols);
    return ptr[i * cols + j];
}

int Matrix::get_lines() const {
    return lines;
}
int Matrix::get_cols() const {
    return cols;
}
void Matrix::display() const {
    for (int i = 0; i < lines; i++) {
        for (int j = 0; j < cols; j++) {
            cout << at(i, j) << " ";
        }
    cout << endl;
    }
}


task4.cpp:
#include "matrix.hpp"
#include <iostream>
#include <cassert>
using std::cin;
using std::cout;
using std::endl;
const int N = 1000;
void output(const Matrix& m, int index) {
    assert(index >= 0 && index < m.get_lines());
    for (auto j = 0; j < m.get_cols(); ++j)
        cout << m.at(index, j) << ", ";
    cout << "\b\b \n";
}
void test1() {
    double x[1000] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

    int n, m;
    cout << "Enter n and m: ";
    cin >> n >> m;

    Matrix m1(n, m);
    m1.set(x);

    Matrix m2(m, n);
    m2.set(x);

    Matrix m3(2);
    m3.set(x);

    cout << "矩阵对象m1: \n";   m1.display();  cout << endl;
    cout << "矩阵对象m2: \n";   m2.display();  cout << endl;
    cout << "矩阵对象m3: \n";   m3.display();  cout << endl;
}
void test2() {
    Matrix m1(2, 3);
    m1.clear();
    const Matrix m2(m1);
    m1.at(0, 0) = -999;
    cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;
    cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;
    cout << "矩阵对象m1第0行: "; output(m1, 0);
    cout << "矩阵对象m2第0行: "; output(m2, 0);
}
int main() {
    cout << "测试1: \n";
    test1();
    cout << "测试2: \n";
    test2();
}

 

任务五

task5.cpp

user.hpp:
#pragma once
#include<vector>
#include<iostream>
#include<string>
using namespace std;
class User {
public:
    User(string n);
    User(string n, string p, string e);
    void set_email();
    void change_password();
    void display();
private:
    string name, password, email;
};
User::User(string n) {
    User::name = n;
    User::password = "123456";
    User::email = "";
}
User::User(string n, string p, string e) {
    User::name = n;
    User::password = p;
    User::email = e;
}
void User::set_email() {
    string e;
    cout << "Enter email address：";
    cin >> e;
    int s = 0;
    while (s != 1) {
        for (int i = 0; i < e.size(); i++) {
            if (e[i] == '@') {
                s = 1;
                break;
            }
        }
        if (s == 1) {
            break;
        }
        else {
            cout << "illegal email.Please re-enter email:";
            cin >> e;
        }
    }
    cout << "email is set successfully..." << endl;
    User::email = e;
}
void User::display() {
    string pas = User::password;
    string pass(pas.size(), '*');
    cout << "name:" << User::name << "\n" << "pass:" << pass << "\n" << "email:" << User::email << endl;
}
void User::change_password() {
    string pas = User::password;
    string p, np;
    cout << "Enter old password:";
    int t = 1;
    for (int i = 0; i < 4; i++) {
        cin >> p;
        if (p == pas && t <3) {
            cout << "Enter new password:";
            cin >> np;
            User::password = np;
            cout << "new password is set successfully..." << endl;
            break;
        }
        else if (p != pas && t <3) {
            cout << "password input error.Please re-enter again:";
            t += 1;
            continue;
        }
        else {
            cout << "password input error.Please try after a while." << endl;
            break;
        }
    }
}


task5.cpp:
#include "user.hpp"
#include <iostream>
#include <vector>
#include <string>
using std::cin;
using std::cout;
using std::endl;
using std::vector;
using std::string;
void test() {
    vector<User> user_lst;
    User u1("Alice", "2024113", "Alice@hotmail.com");
    user_lst.push_back(u1);
    cout << endl;
    User u2("Bob");
    u2.set_email();
    u2.change_password();
    user_lst.push_back(u2);
    cout << endl;
    User u3("Hellen");
    u3.set_email();
    u3.change_password();
    user_lst.push_back(u3);
    cout << endl;
    cout << "There are " << user_lst.size() << " users. they are: " << endl;
    for (auto& i : user_lst) {
        i.display();
        cout << endl;
    }
}
int main() {
    test();
}

 

任务六

task6.cpp

account.h:
#pragma once
#include"date.h"
#include<string>
class SavingsAccount{
private:
    std::string id;
    double balance;
    double rate;
    Date lastDate;
    double accumulation;
    static double total;
    void record(const Date& date, double amount, const std :: string& desc);
    void error(const std::string& msg)const;
    double accumulate(const Date& date)const {
        return accumulation + balance * date.distance(lastDate);
    }
public:
    SavingsAccount(const Date& date, const std::string& id, double rate);
    const std::string& getId()const { return id; }
    double getBalance()const { return balance; }
    double getRate()const { return rate;}
    static double getTotal() { return total; }
    void deposit(const Date& date, double amount, const std::string& desc);
    void withdraw(const Date& date, double amount, const std::string& desc);
    void settle(const Date& date);
    void show()const;
};


date.h:
#pragma once
class Date {
private:
    int year;
    int month;
    int day;
    int totalDays;
public:
    Date(int year, int month, int days);
    int getYear()const{return year;}
    int getDay()const { return day; }
    int getMonth()const { return month; }
    int getMaxDay()const;
    bool isLeapYear()const {
        return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    }
    void show()const;
    int distance(const Date& date)const {
        return totalDays - date.totalDays;
    }
};


account.cpp:
#include"account.h"
#include<iostream>
#include<cmath>
using namespace std;
double SavingsAccount::total = 0;
SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
    date.show();
    cout << "\t#" << id << "created" << endl;
}
void SavingsAccount::record(const Date &date, double amount, const string& desc) {
    accumulation = accumulate(date);
    lastDate = date;
    amount = floor(amount * 100 + 0.5) / 100;
    balance += amount;
    total += amount;
    date.show();
    cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
}
void SavingsAccount::error(const string& msg)const {
    cout << "Error(#" << id << ")" << msg << endl;
}
void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
    record(date, amount, desc);
}
void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
    if (amount > getBalance())
        error("not enougth money");
    else
        record(date, -amount, desc);
}
void SavingsAccount::settle(const Date& date) {
    double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1));
    if (interest != 0)
        record(date, interest, "interest");
    accumulation = 0;
}
void SavingsAccount::show()const {
    cout << id << "\tBalance:" << balance;
}


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();
}


6_25.cpp:
#include"account.h"
#include<iostream>
using namespace std;
int main() {
    Date date(2008, 11, 1);
    SavingsAccount accounts[] = { SavingsAccount(date,"03755217",0.015),SavingsAccount(date,"02342342",0.015) };
    const int n = sizeof(accounts) / sizeof(SavingsAccount);
    accounts[0].deposit(Date(2008, 11,5), 5000, "salary");
    accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323"); 
    accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");
    accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
    cout << endl;
    for (int i = 0; i < n; i++) {
        accounts[i].settle(Date(2009, 1, 1));
        accounts[i].show();
        cout << endl;
    }
    cout << "Total:" << SavingsAccount::getTotal() << endl;
    return 0;
}