实验3 c++
任务一：
button.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));
}
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();
}
实验结果截图：
问题一：自定义了两个类使用了标准库的iostream，string，vector类，button类和iostream，string组合，window类和button，iostream，vector类组合
问题二：如果成员函数只是访问数据而不改变数据，就可以加上const来增加代码的安全性。如果函数简单并且调用频繁，则可以加上inline来提高性能
问题三：代码的功能是生成一条分割线，可用于装饰和视觉辅助。
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();
}
实验结果截图：
问题一：创建一个整数向量v1，大小为5，所有元素初始化为42，创建向量v2，复制v1内容，并把v1的第一个元素改为-999。
问题二：创建一个二维向量v1，第一行为1,2,3、第二行为4、5、6、7，后创建一个v1的副本v2，最后在v1第一行的结尾插入-999
问题三：创建一个一维向量t1，拷贝v1第一行的内容，并输出t1的最后一个元素，同理t2。
问题四：vector内部封装的复制构造函数是深复制，为每个元素提供独立的副本。需要提供一个const成员函数作为接口，供const vector使用。
任务三：
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;
}
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();
}
实验结果截图：
问题一：是深复制，为新的代码对象分配了新的内存空间。
问题二：如果返回值改为int无法正确运行测试代码，因为无法通过at修改元素了，有潜在安全隐患，外部代码可能会修改内部数据。
问题三：不可以，如果返回值类型是 vectorint 而不是引用，则每次调用时，都会创建一个vectorint对象的副本。这意味着在函数返回之前，会发生一个完整的对象复制，对性能有显著影响。
任务四：
matrix.hpp：
#include <iostream>
#include <cassert>
#include <iomanip> // 用于 std::setprecision
using std::cout;
using std::endl;
// 类Matrix的实现
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0
Matrix(int n); // 构造函数，构造一个n*n的矩阵, 初始值为0
Matrix(const Matrix& x); // 复制构造函数，使用已有的矩阵X构造
~Matrix(); // 析构函数
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; // 指向矩阵数据的指针
};
// 构造函数（n x m 矩阵）
Matrix::Matrix(int n, int m) : lines(n), cols(m) {
ptr = new double[lines * cols](); // 初始化为0
}
// 构造函数（n x n 矩阵）
Matrix::Matrix(int n) : Matrix(n, n) {}
// 复制构造函数
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]; // 深复制数据
}
}
// 析构函数
Matrix::~Matrix() {
delete[] ptr; // 释放分配的内存
}
// 设置矩阵数据
void Matrix::set(const double* pvalue) {
for (int i = 0; i < lines * cols; ++i) {
ptr[i] = pvalue[i];
}
}
// 清空矩阵
void Matrix::clear() {
for (int i = 0; i < lines * cols; ++i) {
ptr[i] = 0.0;
}
}
// 获取元素的 const 引用
const double& Matrix::at(int i, int j) const {
assert(i >= 0 && i < lines && j >= 0 && j < cols); // 边界检查
return ptr[i * cols + j]; // 计算并返回元素
}
// 获取元素的引用
double& Matrix::at(int i, int j) {
assert(i >= 0 && i < lines && j >= 0 && j < cols); // 边界检查
return ptr[i * cols + j]; // 计算并返回元素
}
// 返回行数
int Matrix::get_lines() const {
return lines;
}
// 返回列数
int Matrix::get_cols() const {
return cols;
}
// 显示矩阵
void Matrix::display() const {
for (int i = 0; i < lines; ++i) {
for (int j = 0; j < cols; ++j) {
cout << std::setw(1) << at(i, j) << " "; // 格式化输出
}
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 (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); // 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();
}
实验结果截图：
任务五：
user.hpp:
#pragma once
#include <iostream>
#include <string>
#include <regex> // 用于正则表达式
using std::string;
class User {
private:
string name;
string password;
string email;
public:
// 构造函数，默认密码和邮箱
User(const string& userName, const string& pass = "123456", const string& userEmail = "")
: name(userName), password(pass), email(userEmail) {
}
// 设置邮箱方法
void set_email() {
string inputEmail;
std::regex emailRegex(R"(^[^\s@]+@[^\s@]+\.[^\s@]+$)"); // 简单的邮箱格式检查
do {
std::cout << "Enter your email: ";
std::getline(std::cin, inputEmail);
if (!std::regex_match(inputEmail, emailRegex)) {
std::cout << "Invalid email format. Please try again." << std::endl;
}
} while (!std::regex_match(inputEmail, emailRegex));
email = inputEmail; // 赋值
}
// 修改密码方法
void change_password() {
string oldPassword;
const int maxAttempts = 3;
int attempts = 0;
while (attempts < maxAttempts) {
std::cout << "Enter your old password: ";
std::getline(std::cin, oldPassword);
if (oldPassword == password) {
string newPassword;
std::cout << "Enter your new password: ";
std::getline(std::cin, newPassword);
password = newPassword; // 更新密码
std::cout << "Password changed successfully." << std::endl;
return;
}
else {
std::cout << "Incorrect password. Try again." << std::endl;
attempts++;
}
}
std::cout << "Too many failed attempts. Please try again later." << std::endl;
}
// 显示用户信息
void display() const {
std::cout << "User Name: " << name << "\n"
<< "Password: " << std::string(password.length(), '*') << "\n"
<< "Email: " << email << std::endl;
}
};
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();
}
实验结果截图：
任务六：
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 distance(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();
}
account.h:
#ifndef ACCOUNT_H
#define ACCOUNT_H
#include "date.h"
#include <string>
class SavingsAccount {
private:
// 储蓄账户类
std::string id;
double balance;
// 账号
double rate;
// 余额
Date lastDate;
// 存款的年利率
double accumulation;
// 上次变更余额的时期
static double total;
// 余额按日累加之和
// 所有账户的总金额
// 记录一笔账, date为日期, amount为金额, desc为说明
void record(const Date& date, double amount, const std::string& desc);
// 报告错误信息
void error(const std::string& msg) const;
// 获得到指定日期为止的存款金额按日累积值
double accumulate(const Date& date) const {
return accumulation + balance * date.distance(lastDate);
}
public:
// 构造函数
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; }
// 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);
// 结算利息, 每年1月1日调用一次该函数
void settle(const Date& date);
// 打印账户信息
void show() const;
};
#endif // ACCOUNT_H
account.cpp:
// account.cpp
#include "account.h"
#include <cmath>
#include <iostream>
using namespace std;
double SavingsAccount::total = 0;
// SavingsAccount类相关成员函数的实现
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; // 保留小数点后两位
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 enough money");
}
else {
record(date, -amount, desc);
}
}
void SavingsAccount::settle(const Date& date) {
double interest = accumulate(date) * rate; // 计算年息
date.distance(Date(date.getYear() - 1, 1, 1)); //这部分代码在给出的代码中被注释或省略了
if (interest != 0) {
record(date, interest, " interest");
accumulation = 0; // 结算后清零
}
}
void SavingsAccount::show() const {
cout << id << "\tbalance: " << balance;
}
6_25.cpp:
// 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;
}
实验结果截图：
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