任务一：
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();
}
运行结果截图：
问题一：
自定义了两个类Window和Botton，使用了vector和string，其中window和button，vector有关，button和string有关
问题二：
不适合，过多的添加inline函数会使代码运行时可执行体积变大，导致程序运行变慢，而const多用于修饰常数，不可随意添加
问题三：
定义一个大小为40的*数组s
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：
1：创建一个大小为5的数组v1，且每个元素初始值为42.
2：将v1里的数据复制到v2。
3：将v1中的第一个元素赋值为-999。
问题2：
1：创建了一个二维数组v1，且初始化第一行为1,2,3第二行为4,5,6,7；
2：将v1的数据复制到v2中，且v2的值不可改变。
3：在v1的第一行的最后插入-999。
问题3：
1：将v1中地址为0的数组赋值t1。
2：输出t1中的最后一个元素。
3：将v2中地址为0的数组赋值给t2。
4：输出t2中的最后一个元素。
问题4：深复制 需要。
任务3：
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();
}
问题1：
深复制
问题2：
不能运行，左操作数必须为左值
问题3：
可以，但会占用额外内存。
任务4；
Matrix.h:
#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
// xxx
task4.cpp
#include "Matrix.h"
#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();
}
Matrix.cpp:
#include <iostream>
#include "Matrix.h"
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) : lines(x.lines), cols(x.cols) {
ptr = new double[lines * cols];
std::copy(x.ptr, x.ptr + lines * cols, ptr);
}
Matrix::~Matrix() {
delete[] ptr;
}
void Matrix::set(const double *pvalue) {
std::copy(pvalue, pvalue + lines * cols, ptr);
}
void Matrix::clear() {
std::fill(ptr, ptr + lines * cols, 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;
}
}
任务5：
user.cpp
#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;
}
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", "[email protected]");
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6：
task6.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;
}
标签：std,const,cout,int,实验,include,Matrix From： https://www.cnblogs.com/Jjjzz1/p/18538456