实验三

task 1

main.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();
}

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));
}

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";
}

运行截图

问题1：定义了botton和window类，使用了标准库的string和vector类，button类中使用了string类，window类中使用了botton类和vector类

问题2：不适合 不应该设置成inline，因为它可能不是频繁调用的小函数，且可能需要从外部访问。

问题3：的功能是创建一个长度为40、填充字符为*的字符串s。这个字符串用于在控制台输出窗口的边框。

task 2

#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();
}

 问题一：第一行代码创建了一个包含5个元素的vector<int>并把元素初始化为42。

                第二行代码创建了另一个vector<int>，它通过复制构造函数复制了v1。

                第三行代码将v1的第一个元素修改为-999。

 问题二：第一行代码创建了一个包含两个vector<int>的vector，每个vector<int>分别包含3个元素。

               第二行代码创建了一个v1的常量副本v2。

               第三行代码在v1的第一个vector<int>的末尾端添加了元素-999

问题三：第一行代码创建了一个vector<int>的副本t1，它是v1的第一个vector<int>。

              第二行代码打印了t1的最后一个元素。

              第三行代码创建了v2的第一个vector<int>的常量副本t2。

               第四行代码打印了t2的最后一个元素。

问题四：深复制  需要接口

task 3

main.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();
}

vectorInt.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;
}

运行截图

 问题一：深复制

问题二：不能正确运行

              有安全隐患，违反 const 对象的常量性质，可能导致程序中的其他部分代码出现未定义行为

 问题三：可以。这样使代码更加简洁但也会导致混淆

task 4

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);           // 构造函数，构造一个n*m的矩阵, 初始值为value
    Matrix(int n);                  // 构造函数，构造一个n*n的矩阵, 初始值为value
    Matrix(const Matrix &x);        // 复制构造函数， 使用已有的矩阵X构造
    ~Matrix();

    void set(const double *pvalue);         // 用pvalue指向的连续内存块数据按行为矩阵赋值
    void clear();                           // 把矩阵对象的值置0

    const double& at(int i, int j) const;   // 返回矩阵对象索引(i,j)的元素const引用
    double& at(int i, int j);               // 返回矩阵对象索引(i,j)的元素引用

    int get_lines() const;                  // 返回矩阵对象行数
    int get_cols() const;                   // 返回矩阵对象列数

    void display() const;                    // 按行显示矩阵对象元素值

private:
    int lines;      // 矩阵对象内元素行数
    int cols;       // 矩阵对象内元素列数
    double *ptr;
};

// 类Matrix的实现：待补足
Matrix::Matrix(int n, int m) : lines(n), cols(m) {
    ptr = new double[lines * cols]();
}

Matrix::Matrix(int n) : lines(n), cols(n) {
    ptr = new double[lines * cols]();
}

Matrix::Matrix(const Matrix &x) : lines(x.lines), cols(x.cols) {
    ptr = new double[lines * cols];
    for (int i = 0; i < lines * 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 << ptr[i * cols + 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;

// 输出矩阵对象索引为index所在行的所有元素
void output(const Matrix &m, int index) {
    assert(index >= 0 && index < m.get_lines());

    for(int 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);    // 创建矩阵对象m1, 大小n×m
    m1.set(x);          // 用一维数组x的值按行为矩阵m1赋值

    Matrix m2(m, n);    // 创建矩阵对象m1, 大小m×n
    m2.set(x);          // 用一维数组x的值按行为矩阵m1赋值

    Matrix m3(2);       // 创建一个2×2矩阵对象
    m3.set(x);          // 用一维数组x的值按行为矩阵m4赋值

    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();
}

task 5

main.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();
}

user.hpp

#include <iostream>
#include <string>

class User {
public:
    // 构造函数
    User(const std::string& name, const std::string& password = "123456", const std::string& email = "");
    
    // 设置邮箱
    void set_email();
    
    // 修改密码
    void change_password();
    
    // 显示用户信息
    void display();

private:
    std::string name;   // 用户名
    std::string password; // 密码
    std::string email;   // 邮箱
};

// 构造函数
User::User(const std::string& name, const std::string& password, const std::string& email)
    : name(name), password(password), email(email) {}

// 设置邮箱
void User::set_email() {
    std::string input;
    std::cout << "Enter email for " << name << ": ";
    std::cin.ignore(); // 忽略之前读取的换行符
    std::getline(std::cin, input);
    while (input.find('@') == std::string::npos) {
        std::cout << "Invalid email. Please enter a valid email: ";
        std::getline(std::cin, input);
    }
    email = input;
}

// 修改密码
void User::change_password() {
    std::string old_password, new_password, confirm_password;
    std::cout << "Enter old password: ";
    std::cin.ignore();
    std::getline(std::cin, old_password);
    int attempts = 0;
    while (old_password != password && attempts < 3) {
        std::cout << "Incorrect password. Try again: ";
        std::getline(std::cin, old_password);
        attempts++;
    }
    if (attempts == 3) {
        std::cout << "Too many failed attempts. Exiting password change." << std::endl;
        return;
    }
    std::cout << "Enter new password: ";
    std::getline(std::cin, new_password);
    std::cout << "Confirm new password: ";
    std::getline(std::cin, confirm_password);
    if (new_password == confirm_password) {
        password = new_password;
    } else {
        std::cout << "Passwords do not match. Password change cancelled." << std::endl;
    }
}

// 显示用户信息
void User::display() {
    std::cout << "Username: " << name << ", Password: " << std::string(password.size(), '*') << ", Email: " << email << std::endl;
}

运行截图

task 6

main.cpp

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

int main(){
    SavingAccount sa0(1,21325302,0.015);
    SavingAccount 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:"<<SavingAccount::getTotal()<<endl;
    return 0;
}

account.cpp

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

double SavingAccount::total=0;

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

account.h

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

double SavingAccount::total=0;

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