实验一：
代码：
button.hpp:
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 }
windows.hpp:
1 #pragma once
2 #include "button.hpp"
3 #include <vector>
4 #include <iostream>
5
6 using std::vector;
7 using std::cout;
8 using std::endl;
9
10 // 窗口类
11 class Window{
12 public:
13 Window(const string &win_title);
14 void display() const;
15 void close();
16 void add_button(const string &label);
17
18 private:
19 string title;
20 vector<Button> buttons;
21 };
22
23 Window::Window(const string &win_title): title{win_title} {
24 buttons.push_back(Button("close"));
25 }
26
27 inline void Window::display() const {
28 string s(40, '*');
29
30 cout << s << endl;
31 cout << "window title: " << title << endl;
32 cout << "It has " << buttons.size() << " buttons: " << endl;
33 for(const auto &i: buttons)
34 cout << i.get_label() << " button" << endl;
35 cout << s << endl;
36 }
37
38 void Window::close() {
39 cout << "close window '" << title << "'" << endl;
40 buttons.at(0).click();
41 }
42
43 void Window::add_button(const string &label) {
44 buttons.push_back(Button(label));
45 }
task1.cpp:
1 #include "window.hpp"
2 #include <iostream>
3
4 using std::cout;
5 using std::cin;
6
7 void test() {
8 Window w1("new window");
9 w1.add_button("maximize");
10 w1.display();
11 w1.close();
12 }
13
14 int main() {
15 cout << "用组合类模拟简单GUI:\n";
16 test();
17 }
运行结果：
问题1：自定义了两个类，用了标准库的vector类；window类包含vector数组，数组元素类型为button对象。
问题2：不适合，const是为了保证数据不被修改，而inline是为了让函数内联，加快程序运行速度。
问题3：定义一个字符串s,其内容为40个*。
实验二：
代码：
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 }
运行结果：
问题1：第一行是构造vector数组v1，类型为整型，初始有5个元素，每个元素都是42；第二行是构造vector数组v2，类型为整型，内容复制v1；第三行是用vector数组的at（）函数，索引vector数组0号位置的元素，将其改为-999。
问题2：第一行是构造vector数组v1，类型为vector整型数组类型，第一个vector数组元素赋值为1，2，3。第二个vector数组元素赋值为4，5，6，7;第二行是构造vector数组v2，类型为vector整型数组类型，内容复制v1，并且不可以修改；第三行是索引v1数组0号元素，将-999插入末尾。
问题3：第一行是构造vector整型数组t1，内容为v1数组的首个元素；第二行是输出t1的末尾元素并换行；第三行是构造vector整型数组t2，内容为v2的首个元素，并且不可以修改；第四行是输出t2的末尾元素并换行。
问题4：（1）深复制，因为改变被复制对象的元素，复制对象的元素不会跟着改变。
(2)需要，因为有时使用at不需要改变其值，只需要输出值，此时用const成员函数可以保证值不会被改变。
实验三：
代码：
vectorInt.hpp:
1 #pragma once
2
3 #include <iostream>
4 #include <cassert>
5
6 using std::cout;
7 using std::endl;
8
9 // 动态int数组对象类
10 class vectorInt{
11 public:
12 vectorInt(int n);
13 vectorInt(int n, int value);
14 vectorInt(const vectorInt &vi);
15 ~vectorInt();
16
17 int& at(int index);
18 const int& at(int index) const;
19
20 vectorInt& assign(const vectorInt &v);
21 int get_size() const;
22
23 private:
24 int size;
25 int *ptr; // ptr指向包含size个int的数组
26 };
27
28 vectorInt::vectorInt(int n): size{n}, ptr{new int[size]} {
29 }
30
31 vectorInt::vectorInt(int n, int value): size{n}, ptr{new int[size]} {
32 for(auto i = 0; i < size; ++i)
33 ptr[i] = value;
34 }
35
36 vectorInt::vectorInt(const vectorInt &vi): size{vi.size}, ptr{new int[size]} {
37 for(auto i = 0; i < size; ++i)
38 ptr[i] = vi.ptr[i];
39 }
40
41 vectorInt::~vectorInt() {
42 delete [] ptr;
43 }
44
45 const int& vectorInt::at(int index) const {
46 assert(index >= 0 && index < size);
47
48 return ptr[index];
49 }
50
51 int& vectorInt::at(int index) {
52 assert(index >= 0 && index < size);
53
54 return ptr[index];
55 }
56
57 vectorInt& vectorInt::assign(const vectorInt &v) {
58 delete[] ptr; // 释放对象中ptr原来指向的资源
59
60 size = v.size;
61 ptr = new int[size];
62
63 for(int i = 0; i < size; ++i)
64 ptr[i] = v.ptr[i];
65
66 return *this;
67 }
68
69 int vectorInt::get_size() const {
70 return size;
71 }
task3.cpp:
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 }
运行结果：
问题1：深复制。
问题2：不能，因为&代表引用，返回值引用原来的对象的成员，如果修改对象的成员也会跟着改变，达到目的，如果去掉就无法成功改变值。const去掉会有安全隐患，因为const表明他的返回值是const int类型，不能修改。
问题3：不能，因为返回值是引用被复制后的vectorInt对象，是原来的被改变的对象，如果去掉就返回一个新的复制的对象。会占用多于内存。
实验四：
代码：
matrix.hpp:
1 #pragma once
2
3 #include<iostream>
4 #include<cassert>
5
6 using std::cout;
7 using std::endl;
8
9 class Matrix {
10 public:
11 Matrix(int n, int m);
12 Matrix(int n);
13 Matrix(const Matrix& x);
14 ~Matrix();
15
16 void set(const double* pvalue);
17 void clear();
18
19 const double& at(int i, int j)const;
20 double& at(int i, int j);
21
22 int get_lines()const;
23 int get_cols()const;
24
25 void display()const;
26
27 private:
28 int lines;
29 int cols;
30 double* ptr;
31 };
32
33 Matrix::Matrix(int n, int m) :lines{ n }, cols{ m } {
34 ptr = new double [n*m];
35 }
36
37 Matrix::Matrix(int n) :lines{ n }, cols{ n } {
38 ptr = new double[n * n];
39 }
40
41 Matrix::Matrix(const Matrix& x) {
42 lines = x.lines;
43 cols = x.cols;
44 ptr = new double[lines * cols];
45 for (int i = 0; i < lines * cols; i++)
46 ptr[i] = x.ptr[i];
47 }
48
49 Matrix::~Matrix() {
50 delete[]ptr;
51 }
52
53 void Matrix::set(const double* pvalue) {
54 for (int i = 0; i < lines * cols; i++) {
55 ptr[i] = pvalue[i];
56 }
57 }
58
59 void Matrix::clear() {
60 for (int i = 0; i < lines * cols; i++) {
61 ptr[i] = 0;
62 }
63 }
64
65 const double& Matrix::at(int i, int j)const {
66 return ptr[i * cols + j];
67 }
68
69 double& Matrix::at(int i, int j) {
70 return ptr[i * cols + j];
71 }
72
73 int Matrix::get_lines()const {
74 return lines;
75 }
76
77 int Matrix::get_cols()const {
78 return cols;
79 }
80
81 void Matrix::display()const {
82 for (int i = 0; i < lines * cols; i++) {
83 if ((i + 1) % cols != 0)
84 cout << ptr[i] << " ,";
85 else
86 cout << ptr[i] << endl;
87 }
88 }
task4.cpp:
1 #include"matrix.hpp"
2 #include<iostream>
3 #include<cassert>
4
5 using std::cin;
6 using std::cout;
7 using std::endl;
8
9 const int N = 1000;
10
11 void output(const Matrix& m, int index) {
12 assert(index >= 0 && index < m.get_lines());
13
14 for (auto j = 0; j < m.get_cols(); j++)
15 cout << m.at(index, j) << ",";
16 cout << "\b\b\n";
17 }
18
19 void test1() {
20 double x[1000] = { 5,6,7,8,9,10,11,12,13,14 };
21
22 int n, m;
23 cout << "Enter n and m:";
24 cin >> n >> m;
25
26 Matrix m1(n, m);
27 m1.set(x);
28
29 Matrix m2(m, n);
30 m2.set(x);
31
32 Matrix m3(2);
33 m3.set(x);
34
35 cout << "矩阵对象m1:\n"; m1.display(); cout << endl;
36 cout << "矩阵对象m2:\n"; m2.display(); cout << endl;
37 cout << "矩阵对象m3:\n"; m3.display(); cout << endl;
38 }
39
40 void test2() {
41 Matrix m1(2, 3);
42 m1.clear();
43
44 const Matrix m2(m1);
45 m1.at(0, 0) = -999;
46
47 cout << "m1.at(0,0)=" << m1.at(0, 0) << endl;
48 cout << "m2.at(0,0)=" << m2.at(0, 0) << endl;
49 cout << "矩阵对象m1第0行："; output(m1, 0);
50 cout << "矩阵对象m2第0行："; output(m2, 0);
51 }
52
53 int main() {
54 cout << "测试1：\n";
55 test1();
56
57 cout << "测试2：\n";
58 test2();
59 }
运行结果：
实验五：
代码：
user.hpp:
1 #pragma once
2 #include<iostream>
3 #include<string>
4
5 using namespace std;
6
7 class User {
8 public:
9 User(string n) :name{ n } {
10 password = "123456";
11 email = " ";
12 }
13 User(string n, string p, string e) :name{ n }, password{ p }, email{ e } {
14 }
15
16 void set_email() {
17 int judge = 0;
18 string e;
19 cout << "请输入邮箱：";
20 while(judge!=1){
21 cin >> e;
22 for (char i : e) {
23 if (i == '@') {
24 judge = 1;
25 break;
26 }
27 }
28 if (judge == 1)break;
29 else
30 cout << "不是合法邮箱，请重新输入：";
31 }
32 email = e;
33 cout << "邮箱设置成功"<<endl;
34 }
35
36 void change_password() {
37 int times=0;
38 string oldp,newp;
39 cout << "输入旧密码：";
40 do {
41 cin >> oldp;
42 if (oldp == password)
43 break;
44 else times++;
45 cout << "密码错误，请重新输入密码：";
46 if (times == 3) {
47 cout << "连续三次输入错误，请稍后再试" << endl;
48 return;
49 }
50 } while (true);
51 cout << "请输入新密码：";
52 cin >> newp;
53 password = newp;
54 cout << "新密码设置成功" << endl;
55 }
56
57 void display() {
58 int length = 0;
59 length = password.size();
60 string protection(length, '*');
61 cout << "name: " << name << endl;
62 cout << "pass: " << protection << endl;
63 cout << "email: " << email << endl;
64 cout << endl;
65 }
66 private:
67 string name, password, email;
68 };
task5.cpp:
1 #include"user.hpp"
2 #include<iostream>
3 #include<vector>
4 #include<string>
5
6 using std::cin;
7 using std::cout;
8 using std::endl;
9 using std::vector;
10 using std::string;
11
12 void test() {
13 vector<User>user_1st;
14
15 User u1("Alice", "2024113", "[email protected]");
16 user_1st.push_back(u1);
17 cout << endl;
18
19 User u2("Bob");
20 u2.set_email();
21 u2.change_password();
22 user_1st.push_back(u2);
23 cout << endl;
24
25 User u3("Hellen");
26 u3.set_email();
27 u3.change_password();
28 user_1st.push_back(u3);
29 cout << endl;
30
31 cout << "There are" << user_1st.size() << "users.they are::" << endl;
32 for (auto& i : user_1st) {
33 i.display();
34 cout << endl;
35 }
36 }
37
38 int main() {
39 test();
40 }
运行结果：
实验六：
代码：
date.h:
1 #pragma once
2 #ifndef DATE H
3 #define DATE H
4 class Date {
5 private:
6 int year;
7 int month;
8 int day;
9 int totalDays;
10 public:
11 Date(int year, int month, int day);
12 int getYear()const { return year; }
13 int getMonth()const { return month; }
14 int getDay()const { return day; }
15 int getMaxDay()const;
16 bool isLeapYear()const {
17 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
18 }
19 void show()const;
20 int distance(const Date& date)const {
21 return totalDays - date.totalDays;
22 }
23 };
24 #endif //DATE H
date.cpp:
1 #include"date.h"
2 #include<iostream>
3 #include<cstdlib>
4 using namespace std;
5 namespace {
6 const int DAYS_BEFORE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 };
7 }
8 Date::Date(int year, int month, int day) :year{ year }, month{ month }, day{ day } {
9 if (day <= 0 || day > getMaxDay()) {
10 cout << "Invalid date:";
11 show();
12 cout << endl;
13 exit(1);
14 }
15 int years = year - 1;
16 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
17 if (isLeapYear() && month > 2)totalDays++;
18 }
19 int Date::getMaxDay()const {
20 if (isLeapYear() && month == 2)
21 return 29;
22 else
23 return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
24 }
25 void Date::show()const {
26 cout << getYear() << "-" << getMonth() << "-" << getDay();
27 }
account.h:
1 #pragma once
2 #ifndef ACCOUNT H
3 #define ACCOUNT H
4 #include"date.h"
5 #include<string>
6 class SavingsAccount {
7 private:
8 std::string id;
9 double balance;
10 double rate;
11 Date lastDate;
12 double accumulation;
13 static double total;
14
15 void record(const Date& date, double amount, const std::string& desc);
16
17 void error(const std::string& msg)const;
18
19 double accumulate(const Date& date)const {
20 return accumulation + balance * date.distance(lastDate);
21 }
22 public:
23 SavingsAccount(const Date& date, const std::string& id, double rate);
24 const std::string& getId()const { return id; }
25 double getBalance()const { return balance; }
26 double getRate()const { return rate; }
27 static double getTotal() { return total; }
28
29 void deposit(const Date& date, double amount, const std::string& desc);
30
31 void withdraw(const Date& date, double amount, const std::string& desc);
32
33 void settle(const Date& date);
34
35 void show()const;
36 };
37 #endif// ACCOUNT H
account.cpp:
1 #include"account.h"
2 #include<iostream>
3 #include<cmath>
4 using namespace std;
5 double SavingsAccount::total = 0;
6
7 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :id{ id }, balance{ 0 }, rate{ rate }, lastDate{ date }, accumulation{ 0 } {
8 date.show();
9 cout << "\t#" << id << "created" << endl;
10 }
11
12 void SavingsAccount::record(const Date& date, double amount, const string& desc) {
13 accumulation = accumulate(date);
14 lastDate = date;
15 amount = floor(amount * 100 + 0.5) / 100;
16 balance+= amount;
17 total += amount;
18 date.show();
19 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
20 }
21
22 void SavingsAccount::error(const string& msg)const {
23 cout << "Error(#" << id << "):" << msg << endl;
24 }
25
26 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
27 record(date, amount, desc);
28 }
29
30 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
31 if (amount > getBalance())
32 error("not enough money");
33 else
34 record(date, -amount, desc);
35 }
36
37 void SavingsAccount::settle(const Date& date) {
38 double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1));
39 if (interest != 0)
40 record(date, interest, "interest");
41 accumulation = 0;
42 }
43
44 void SavingsAccount::show()const {
45 cout << id << "\tBalance:" << balance;
46 }
6_25.cpp:
1 #include"account.h"
2 #include<iostream>
3 using namespace std;
4 int main() {
5 Date date(2008, 11, 1);
6
7 SavingsAccount accounts[] = {
8 SavingsAccount(date,"03755217",0.015),SavingsAccount(date,"02342342",0.015)
9 };
10 const int n = sizeof(accounts) / sizeof(SavingsAccount);
11
12 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");
13 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
14
15 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");
16 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
17
18 cout << endl;
19 for (int i = 0; i < n; i++) {
20 accounts[i].settle(Date(2009, 1, 1));
21 accounts[i].show();
22 cout << endl;
23 }
24 cout << "Total:" << SavingsAccount::getTotal() << endl;
25 return 0;
26 }
运行结果：
