1 #pragma once
2
3 #include <iostream>
4 #include <string>
5
6 using std::string;
7 using std::cout;
8
9 // 按钮类
10 class Button {
11 public:
12 Button(const string &text);
13 string get_label() const;
14 void click();
15
16 private:
17 string label;
18 };
19
20 Button::Button(const string &text): label{text} {
21 }
22
23 inline string Button::get_label() const {
24 return label;
25 }
26
27 void Button::click() {
28 cout << "Button '" << label << "' clicked\n";
29 }
30
31
32
33 #pragma once
34 #include "button.hpp"
35 #include <vector>
36 #include <iostream>
37
38 using std::vector;
39 using std::cout;
40 using std::endl;
41
42 // 窗口类
43 class Window{
44 public:
45 Window(const string &win_title);
46 void display() const;
47 void close();
48 void add_button(const string &label);
49
50 private:
51 string title;
52 vector<Button> buttons;
53 };
54
55 Window::Window(const string &win_title): title{win_title} {
56 buttons.push_back(Button("close"));
57 }
58
59 inline void Window::display() const {
60 string s(40, '*');
61
62 cout << s << endl;
63 cout << "window title: " << title << endl;
64 cout << "It has " << buttons.size() << " buttons: " << endl;
65 for(const auto &i: buttons)
66 cout << i.get_label() << " button" << endl;
67 cout << s << endl;
68 }
69
70 void Window::close() {
71 cout << "close window '" << title << "'" << endl;
72 buttons.at(0).click();
73 }
74
75 void Window::add_button(const string &label) {
76 buttons.push_back(Button(label));
77 }
78
79
80
81
82 #include "window.hpp"
83 #include <iostream>
84
85 using std::cout;
86 using std::cin;
87
88 void test() {
89 Window w1("new window");
90 w1.add_button("maximize");
91 w1.display();
92 w1.close();
93 }
94
95 int main() {
96 cout << "用组合类模拟简单GUI:\n";
97 test();
98 }
task1
1.两个类window和button 两个标准库类string和vector。
2.没必要。剩下的函数执行时不会改变对象值。
3.定义一个对象s，其长度为40且都是“*”。
1 #include <iostream>
2 #include <vector>
3
4 using namespace std;
5
6 void output1(const vector<int> &v) {
7 for(auto &i: v)
8 cout << i << ", ";
9 cout << "\b\b \n";
10 }
11
12 void output2(const vector<vector<int>> v) {
13 for(auto &i: v) {
14 for(auto &j: i)
15 cout << j << ", ";
16 cout << "\b\b \n";
17 }
18 }
19
20 void test1() {
21 vector<int> v1(5, 42);
22 const vector<int> v2(v1);
23
24 v1.at(0) = -999;
25 cout << "v1: "; output1(v1);
26 cout << "v2: "; output1(v2);
27 cout << "v1.at(0) = " << v1.at(0) << endl;
28 cout << "v2.at(0) = " << v2.at(0) << endl;
29 }
30
31 void test2() {
32 vector<vector<int>> v1{{1, 2, 3}, {4, 5, 6, 7}};
33 const vector<vector<int>> v2(v1);
34
35 v1.at(0).push_back(-999);
36 cout << "v1: \n"; output2(v1);
37 cout << "v2: \n"; output2(v2);
38
39 vector<int> t1 = v1.at(0);
40 cout << t1.at(t1.size()-1) << endl;
41
42 const vector<int> t2 = v2.at(0);
43 cout << t2.at(t2.size()-1) << endl;
44 }
45
46 int main() {
47 cout << "测试1:\n";
48 test1();
49
50 cout << "\n测试2:\n";
51 test2();
52 }
task2
1.定义一个长度为5的一维数组，其元素均为42；定义一个和v1相同的数组v2；将v1中第一个元素修改为-999。
2.定义一个二维数组v1，第一行为123，第二行为4567；定义一个和v1相同且值不能改变的数组v2；在v1第一行末尾插入一个值-999。
3.定义一个数组t1，其元素为v1的第一行元素，输出t1的最后一个元素；定义一个不能改变的数组v2，其值为v2的第一行元素，输出t2的最后一个元素。
4.深复制；是
1 #include "vectorInt.hpp"
2 #include <iostream>
3
4 using std::cin;
5 using std::cout;
6
7 void output(const vectorInt &vi) {
8 for(auto i = 0; i < vi.get_size(); ++i)
9 cout << vi.at(i) << ", ";
10 cout << "\b\b \n";
11 }
12
13
14 void test1() {
15 int n;
16 cout << "Enter n: ";
17 cin >> n;
18
19 vectorInt x1(n);
20 for(auto i = 0; i < n; ++i)
21 x1.at(i) = i*i;
22 cout << "x1: "; output(x1);
23
24 vectorInt x2(n, 42);
25 vectorInt x3(x2);
26 x2.at(0) = -999;
27 cout << "x2: "; output(x2);
28 cout << "x3: "; output(x3);
29 }
30
31 void test2() {
32 const vectorInt x(5, 42);
33 vectorInt y(10, 0);
34
35 cout << "y: "; output(y);
36 y.assign(x);
37 cout << "y: "; output(y);
38
39 cout << "x.at(0) = " << x.at(0) << endl;
40 cout << "y.at(0) = " << y.at(0) << endl;
41 }
42
43 int main() {
44 cout << "测试1: \n";
45 test1();
46
47 cout << "\n测试2: \n";
48 test2();
49 }
50
51
52
53 #pragma once
54
55 #include <iostream>
56 #include <cassert>
57
58 using std::cout;
59 using std::endl;
60
61 // 动态int数组对象类
62 class vectorInt{
63 public:
64 vectorInt(int n);
65 vectorInt(int n, int value);
66 vectorInt(const vectorInt &vi);
67 ~vectorInt();
68
69 int& at(int index);
70 const int& at(int index) const;
71
72 vectorInt& assign(const vectorInt &v);
73 int get_size() const;
74
75 private:
76 int size;
77 int *ptr; // ptr指向包含size个int的数组
78 };
79
80 vectorInt::vectorInt(int n): size{n}, ptr{new int[size]} {
81 }
82
83 vectorInt::vectorInt(int n, int value): size{n}, ptr{new int[size]} {
84 for(auto i = 0; i < size; ++i)
85 ptr[i] = value;
86 }
87
88 vectorInt::vectorInt(const vectorInt &vi): size{vi.size}, ptr{new int[size]} {
89 for(auto i = 0; i < size; ++i)
90 ptr[i] = vi.ptr[i];
91 }
92
93 vectorInt::~vectorInt() {
94 delete [] ptr;
95 }
96
97 const int& vectorInt::at(int index) const {
98 assert(index >= 0 && index < size);
99
100 return ptr[index];
101 }
102
103 int& vectorInt::at(int index) {
104 assert(index >= 0 && index < size);
105
106 return ptr[index];
107 }
108
109 vectorInt& vectorInt::assign(const vectorInt &v) {
110 delete[] ptr; // 释放对象中ptr原来指向的资源
111
112 size = v.size;
113 ptr = new int[size];
114
115 for(int i = 0; i < size; ++i)
116 ptr[i] = v.ptr[i];
117
118 return *this;
119 }
120
121 int vectorInt::get_size() const {
122 return size;
123 }
task3
1.深复制。
2.不能。存在安全隐患，int&表示新变量与其共享内存，若去掉const，后续新变量值改变时会一起改变原先变量的值。
3.可以。这段代码目的是为了将v的内容赋值给当前对象，若改成vectorint，就是调用复制构造函数生成一个新对象，对结果没有影响。
1 #pragma once
2
3 #include <iostream>
4 #include <cassert>
5
6 using std::cout;
7 using std::endl;
8
9 // 类Matrix的声明
10 class Matrix {
11 public:
12 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵, 初始值为value
13 Matrix(int n); // 构造函数，构造一个n*n的矩阵, 初始值为value
14 Matrix(const Matrix &x); // 复制构造函数， 使用已有的矩阵X构造
15 ~Matrix();
16
17 void set(const double *pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值
18 void clear(); // 把矩阵对象的值置0
19
20 const double& at(int i, int j) const; // 返回矩阵对象索引(i,j)的元素const引用
21 double& at(int i, int j); // 返回矩阵对象索引(i,j)的元素引用
22
23 int get_lines() const; // 返回矩阵对象行数
24 int get_cols() const; // 返回矩阵对象列数
25
26 void display() const; // 按行显示矩阵对象元素值
27
28 private:
29 int lines; // 矩阵对象内元素行数
30 int cols; // 矩阵对象内元素列数
31 double *ptr;
32 };
33
34 // 类Matrix的实现：待补足
35 // xxx
36
37
38
39
40
41 #include "matrix.hpp"
42 #include <iostream>
43 #include <cassert>
44
45 using namespace std;
46
47 // 构造函数：使用行数 n 和列数 m 初始化矩阵
48 Matrix::Matrix(int n, int m) : lines(n), cols(m) {
49 assert(n > 0 && m > 0);
50 ptr = new double[n * m](); // 动态分配内存并初始化为 0
51 }
52
53 // 构造函数：初始化为一个 n x n 的方阵
54 Matrix::Matrix(int n) : lines(n), cols(n) {
55 assert(n > 0);
56 ptr = new double[n * n](); // 动态分配内存并初始化为 0
57 }
58
59 // 拷贝构造函数：进行深复制
60 Matrix::Matrix(const Matrix& x) : lines(x.lines), cols(x.cols) {
61 ptr = new double[lines * cols];
62 for (int i = 0; i < lines * cols; ++i) {
63 ptr[i] = x.ptr[i];
64 }
65 }
66
67 // 析构函数：释放动态分配的内存
68 Matrix::~Matrix() {
69 delete[] ptr;
70 }
71
72 // 使用给定的数组 pvalue 初始化矩阵内容
73 void Matrix::set(const double* pvalue) {
74 for (int i = 0; i < lines * cols; ++i) {
75 ptr[i] = pvalue[i];
76 }
77 }
78
79 // 将矩阵所有元素设为 0
80 void Matrix::clear() {
81 for (int i = 0; i < lines * cols; ++i) {
82 ptr[i] = 0;
83 }
84 }
85
86 // 常量版本的 at 函数：获取矩阵中的元素，不能修改
87 const double& Matrix::at(int i, int j) const {
88 assert(i >= 0 && i < lines && j >= 0 && j < cols);
89 return ptr[i * cols + j];
90 }
91
92 // 非常量版本的 at 函数：获取矩阵中的元素，可修改
93 double& Matrix::at(int i, int j) {
94 assert(i >= 0 && i < lines && j >= 0 && j < cols);
95 return ptr[i * cols + j];
96 }
97
98 // 获取矩阵的行数
99 int Matrix::get_lines() const {
100 return lines;
101 }
102
103 // 获取矩阵的列数
104 int Matrix::get_cols() const {
105 return cols;
106 }
107
108 // 输出矩阵的内容
109 void Matrix::display() const {
110 for (int i = 0; i < lines; ++i) {
111 for (int j = 0; j < cols; ++j) {
112 cout << at(i, j) << " ";
113 }
114 cout << endl;
115 }
116 }
117
118
119
120
121 #include "matrix.hpp"
122 #include <iostream>
123 #include <cassert>
124
125 using std::cin;
126 using std::cout;
127 using std::endl;
128
129
130 const int N = 1000;
131
132 // 输出矩阵对象索引为index所在行的所有元素
133 void output(const Matrix &m, int index) {
134 assert(index >= 0 && index < m.get_lines());
135
136 for(auto j = 0; j < m.get_cols(); ++j)
137 cout << m.at(index, j) << ", ";
138 cout << "\b\b \n";
139 }
140
141
142 void test1() {
143 double x[1000] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
144
145 int n, m;
146 cout << "Enter n and m: ";
147 cin >> n >> m;
148
149 Matrix m1(n, m); // 创建矩阵对象m1, 大小n×m
150 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
151
152 Matrix m2(m, n); // 创建矩阵对象m1, 大小m×n
153 m2.set(x); // 用一维数组x的值按行为矩阵m1赋值
154
155 Matrix m3(2); // 创建一个2×2矩阵对象
156 m3.set(x); // 用一维数组x的值按行为矩阵m4赋值
157
158 cout << "矩阵对象m1: \n"; m1.display(); cout << endl;
159 cout << "矩阵对象m2: \n"; m2.display(); cout << endl;
160 cout << "矩阵对象m3: \n"; m3.display(); cout << endl;
161 }
162
163 void test2() {
164 Matrix m1(2, 3);
165 m1.clear();
166
167 const Matrix m2(m1);
168 m1.at(0, 0) = -999;
169
170 cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;
171 cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;
172 cout << "矩阵对象m1第0行: "; output(m1, 0);
173 cout << "矩阵对象m2第0行: "; output(m2, 0);
174 }
175
176 int main() {
177 cout << "测试1: \n";
178 test1();
179
180 cout << "测试2: \n";
181 test2();
182 }
task4
1 #pragma once
2 #include <iostream>
3 #include <string>
4
5 using namespace std;
6
7 class User {
8 private:
9 string name; // 用户名
10 string password; // 密码
11 string email; // 邮箱
12
13 public:
14 // 构造函数：允许仅使用用户名初始化
15 User(const string& n, const string& p = "", const string& e = "")
16 : name(n), password(p), email(e) {}
17
18 // 设置邮箱
19 void set_email() {
20 string input_email;
21 while (true) {
22 cout << "Enter email address: ";
23 cin >> input_email;
24
25 // 简单检查邮箱是否包含 '@' 和 '.' 符号
26 if (input_email.find('@') != string::npos && input_email.find('.') != string::npos) {
27 email = input_email;
28 cout << "Email is set successfully..." << endl;
29 break;
30 } else {
31 cout << "Illegal email. Please re-enter email: ";
32 }
33 }
34 }
35
36 // 修改密码
37 void change_password() {
38 string old_password, new_password, confirm_password;
39
40 cout << "Enter old password: ";
41 cin >> old_password;
42
43 // 检查旧密码是否正确
44 if (old_password == password) {
45 while (true) {
46 cout << "Enter new password: ";
47 cin >> new_password;
48
49 cout << "Please re-enter again: ";
50 cin >> confirm_password;
51
52 // 检查两次输入的密码是否一致
53 if (new_password == confirm_password) {
54 password = new_password;
55 cout << "New password is set successfully..." << endl;
56 break;
57 } else {
58 cout << "Password input error. Please re-enter again." << endl;
59 }
60 }
61 } else {
62 cout << "Password input error. Please try after a while." << endl;
63 }
64 }
65
66 // 显示用户信息
67 void display() const {
68 cout << "Name: " << name << endl;
69 cout << "Pass: " << (password.empty() ? "******" : password) << endl;
70 cout << "Email: " << (email.empty() ? "******" : email) << endl;
71 }
72 };
73
74
75
76
77
78 #include "user.hpp"
79 #include <iostream>
80 #include <vector>
81 #include <string>
82
83 using std::cin;
84 using std::cout;
85 using std::endl;
86 using std::vector;
87 using std::string;
88
89 void test() {
90 vector<User> user_lst;
91
92 User u1("Alice", "2024113", "[email protected]");
93 user_lst.push_back(u1);
94 cout << endl;
95
96 User u2("Bob","123456");
97 u2.set_email();
98 u2.change_password();
99 user_lst.push_back(u2);
100 cout << endl;
101
102 User u3("Hellen");
103 u3.set_email();
104 u3.change_password();
105 user_lst.push_back(u3);
106 cout << endl;
107
108 cout << "There are " << user_lst.size() << " users. they are: " << endl;
109 for(auto &i: user_lst) {
110 i.display();
111 cout << endl;
112 }
113 }
114
115 int main() {
116 test();
117 }
task5
1 #pragma once
2 class Date {
3 private:
4 int year; int month; int day; int totalDays;
5 public:
6 Date(int year, int month, int day);
7 int getYear()const { return year; }
8 int getMonth()const { return month; }
9 int getDay()const { return day; }
10 int getMaxDay()const;
11 bool isLeapYear()const {
12 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
13 }
14 void show()const;
15 int distance(const Date& date)const {
16 return totalDays - date.totalDays;
17 }
18 };
19
20
21 #include"date.h"
22 #include<iostream>
23 #include<cstdlib>
24 using namespace std;
25 namespace {
26 const int DAYS_BEFORE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 };
27 }
28 Date::Date(int year, int month, int day) : year(year), month(month), day(day) {
29 if (day <= 0 || day > getMaxDay()) {
30 cout << "Invalid date:";
31 show();
32 cout << endl;
33 exit(1);
34 }
35 int years = year - 1;
36 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
37 if (isLeapYear() && month > 2)totalDays++;
38 }
39 int Date::getMaxDay()const {
40 if (isLeapYear() && month == 2)
41 return 29;
42 else
43 return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
44 }
45 void Date::show()const {
46 cout << getYear() << "-" << getMonth() << "-" << getDay();
47 }
48
49
50 #include"date.h"
51 #include<string>
52 class SavingsAccount {
53 private:
54 std::string id;
55 double balance;
56 double rate;
57 Date lastDate;
58 double accumulation;
59 static double total;
60 void record(const Date& date, double amount, const std::string& desc);
61 void error(const std::string& msg)const;
62 double accumulate(const Date& date)const {
63 return accumulation + balance * date.distance(lastDate);
64 }
65 public:
66 SavingsAccount(const Date& date, const std::string& id, double rate);
67 const std::string& getId()const { return id; }
68 double getBalance()const { return balance; }
69 double getRate()const { return rate; }
70 static double getTotal() { return total; }
71 void deposit(const Date& date, double amount, const std::string& desc);
72 void withdraw(const Date& date, double amount, const std::string& desc);
73 void settle(const Date& date);
74 void show()const;
75 };
76
77
78 #include"account.h"
79 #include<cmath>
80 #include<iostream>
81 using namespace std;
82 double SavingsAccount::total = 0;
83
84 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
85 date.show();
86 cout << "\t#" << id << "created" << endl;
87 }
88 void SavingsAccount::record(const Date& date, double amount, const std::string& desc) {
89 accumulation = accumulate(date);
90 lastDate = date;
91 amount = floor(amount * 100 + 0.5) / 100;
92 balance += amount;
93 total += amount;
94 date.show();
95 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
96 }
97 void SavingsAccount::error(const std::string& msg)const {
98 cout << "Error(#" << id << ");" << msg << endl;
99 }
100 void SavingsAccount::deposit(const Date& date, double amount, const std::string& desc) {
101 record(date, amount, desc);
102 }
103 void SavingsAccount::withdraw(const Date& date, double amount, const std::string& desc) {
104 if (amount > getBalance())
105 {
106 error("not enough money");
107 }
108 else
109 record(date, -amount, desc);
110 }
111 void SavingsAccount::settle(const Date& date) {
112 double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1));
113 if (interest != 0)
114 record(date, interest, "interest");
115 accumulation = 0;
116 }
117 void SavingsAccount::show()const {
118 cout << id << "\tBalance:" << balance;
119 }
120
121
122 #include"account.h"
123 #include<iostream>
124 using namespace std;
125 int main()
126 {
127 Date date(2008, 11, 1);
128 SavingsAccount accounts[] = {
129 SavingsAccount(date,"03755217",0.015),
130 SavingsAccount(date,"02342342",0.015)
131 };
132 const int n = sizeof(accounts) / sizeof(SavingsAccount);
133 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");
134 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
135
136 accounts[0].deposit(Date(2008, 12, 5), 5000, "salary");
137 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
138
139 cout << endl;
140 for (int i = 0; i < n; i++)
141 {
142 accounts[i].settle(Date(2009, 1, 1));
143 accounts[i].show();
144 cout << endl;
145 }
146 cout << "Total:" << SavingsAccount::getTotal() << endl;
147 return 0;
148 }
task6
标签：std,const,cout,int,void,实验,string From： https://www.cnblogs.com/syxlyw/p/18525835