实验任务一
1 #pragma once
2 #include <iostream>
3 #include <string>
4
5 using std::string;
6 using std::cout;
7
8 // 按钮类
9 class Button {
10 public:
11 Button(const string& text);
12 string get_label() const;
13 void click();
14
15 private:
16 string label;
17 };
18
19 Button::Button(const string& text) : label{ text } {
20 }
21
22 inline string Button::get_label() const {
23 return label;
24 }
25
26 void Button::click() {
27 cout << "Button '" << label << "' clicked\n";
28 }
button.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 }
window.hpp
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 }
task.cpp
问题一：
自定义了两个类window,button,使用了标准库的string,vector，vector包含button，window包含vector，string则被button和window包含。
问题二：
不适合，它们有的改变了类成员，不能设为const函数，有的比较复杂，不适合做内联函数。
问题三：
构造的string可用作分割线。
实验任务二
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.cpp
问题一：
建立vector v1，其中有5个int元素，都为42；建立一个vector v2，用v1赋值；把v1中下表为0的元素改为-999。
问题二：
建立vector v1，其中有2个vector<int>元素；建立一个vector v2，用v1赋值，并设为常量；在v1中下表为0的元素，即第一个vector<int>后插入-999。
问题三：
建立vector t1，用v1中下表为0的元素，即第一个vector<int>赋值；输出t1的最后一项元素；建立vector t2，用v2中下表为0的元素，即第一个vector<int>赋值，因为v2是常量，所以t2必须也是常量；输出t2的最后一项元素。
实验任务三
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 }
vectorint.hpp
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 }
task3.cpp
问题一：
深复制。
问题二：
不行，不返回引用类型无法对原对象操作；不行，不设为const，若ptr值改变，会导致内存泄漏。
问题三：
可以，返回值不使用引用产生的副本是浅复制，是两个不一样但指向相同地址的指针（这个类主要就是个指针）。这样不会占用很多额外内存，对指针指向成员操作也是互通的。但两个指向相同地址的指针容易导致混淆，后续想析构时也很麻烦，所以还是推荐返回值使用引用。
实验任务四
matrix.hpp
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：matrix.cpp
matrix.cpp
1 #include<iostream>
2 #include<cassert>
3 #include"matrix.hpp"
4
5 int value = 0;
6 Matrix::Matrix(int n, int m) :lines{ n }, cols{ m }
7 {
8 ptr = new double[m * n];
9 double* p = ptr;
10 for (int i = 0; i < m * n; i++)
11 {
12 *p = value;
13 p++;
14 }
15 }
16 Matrix::Matrix(int n) :lines{ n }, cols{ n }
17 {
18 ptr = new double[n * n];
19 double* p = ptr;
20 for (int i = 0; i < n * n; i++)
21 {
22 *p = value;
23 p++;
24 }
25 }
26 Matrix::Matrix(const Matrix& x) :lines{ x.lines }, cols{ x.cols }
27 {
28 ptr = new double[x.lines * x.cols];
29 double* p1 = ptr, * p2 = x.ptr;
30 for (int i = 0; i < x.lines * x.cols; i++)
31 {
32 *p1 = *p2;
33 p1++;
34 p2++;
35 }
36 }
37 void Matrix::set(const double* pvalue)
38 {
39 double* p1 = ptr;
40 const double* p2 = pvalue;
41 for (int i = 0; i < lines * cols; i++)
42 {
43 *p1 = *p2;
44 p1++;
45 p2++;
46 }
47 }
48 Matrix::~Matrix()
49 {
50 delete[] ptr;
51 }
52 void Matrix::clear()
53 {
54 double* p = ptr;
55 for (int i = 0; i < lines * cols; i++)
56 {
57 *p = 0;
58 p++;
59 }
60 }
61 const double& Matrix::at(int i, int j) const
62 {
63 return *(ptr + i * cols + j);
64 }
65 double& Matrix::at(int i, int j)
66 {
67 return *(ptr + i * cols + j);
68 }
69 int Matrix::get_lines() const
70 {
71 return lines;
72 }
73 int Matrix::get_cols() const
74 {
75 return cols;
76 }
77 void Matrix::display() const
78 {
79 for (int i = 0; i < lines; i++)
80 {
81 for (int j = 0; j < cols; j++)
82 {
83 cout << *(ptr + i * cols + j) << " ";
84 }
85 cout << endl;
86 }
87 }
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
10 const int N = 1000;
11
12 // 输出矩阵对象索引为index所在行的所有元素
13 void output(const Matrix& m, int index) {
14 assert(index >= 0 && index < m.get_lines());
15
16 for (auto j = 0; j < m.get_cols(); ++j)
17 cout << m.at(index, j) << ", ";
18 cout << "\b\b \n";
19 }
20
21
22 void test1() {
23 double x[1000] = { 1, 3, 5, 7, 9, 11, 13, 15, 17 };
24
25 int n, m;
26 cout << "Enter n and m: ";
27 cin >> n >> m;
28
29 Matrix m1(n, m); // 创建矩阵对象m1, 大小n×m
30 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
31
32 Matrix m2(m, n); // 创建矩阵对象m1, 大小m×n
33 m2.set(x); // 用一维数组x的值按行为矩阵m1赋值
34
35 Matrix m3(2); // 创建一个2×2矩阵对象
36 m3.set(x); // 用一维数组x的值按行为矩阵m4赋值
37
38 cout << "矩阵对象m1: \n"; m1.display(); cout << endl;
39 cout << "矩阵对象m2: \n"; m2.display(); cout << endl;
40 cout << "矩阵对象m3: \n"; m3.display(); cout << endl;
41 }
42
43 void test2() {
44 Matrix m1(2, 3);
45 m1.clear();
46
47 const Matrix m2(m1);
48 m1.at(0, 0) = -999;
49
50 cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;
51 cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;
52 cout << "矩阵对象m1第0行: "; output(m1, 0);
53 cout << "矩阵对象m2第0行: "; output(m2, 0);
54 }
55
56 int main() {
57 cout << "测试1: \n";
58 test1();
59
60 cout << "测试2: \n";
61 test2();
62 }
实验任务五
user.hpp
1 #pragma once
2 #include<iostream>
3 #include<string>
4 using namespace std;
5
6 class User
7 {
8 private:
9 string name, password, email;
10 public:
11 User(string x);
12 User(string x, string y, string z);
13 void set_email();
14 void change_password();
15 void display() const;
16 };
17 User::User(string x) :name{ x }
18 {
19 password = "123456";
20 email = "\0";
21 }
22 User::User(string x, string y, string z) :name{ x }, password{ y }, email{ z }{}
23 void User::set_email()
24 {
25 cout << "请输入邮箱：";
26 cin >> email;
27 int t = 1;
28 while(t)
29 {
30 for (char c : email)
31 {
32 if (c == '@')
33 t = 0;
34 }
35 if (t == 0);
36 else
37 {
38 cout << "邮箱格式错误，请再次输入：";
39 cin >> email;
40 }
41 }
42 cout << "邮箱成功创建" << endl;
43 }
44 void User::change_password()
45 {
46 string old;
47 cout << "请输入旧密码：";
48 cin >> old;
49 int i = 2;
50 while (old != password&&i)
51 {
52 cout << "密码输入错误，请重新输入：";
53 cin >> old;
54 i--;
55 }
56 if (i == 0)
57 {
58 cout << "密码输入错误次数过多，请稍后再试";
59 }
60 else
61 {
62 cout << "请输入新密码";
63 cin >> password;
64 }
65 }
66
67 void User::display() const
68 {
69 cout << "name: " << name << endl;
70 cout << "pass:";
71 for (int i = 0; i < password.size(); i++)
72 {
73 cout << "*";
74 }
75 cout << endl;
76 cout << "email:" << email << endl;
77 }
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_lst;
14
15 User u1("Alice", "2024113", "[email protected]");
16 user_lst.push_back(u1);
17 cout << endl;
18
19 User u2("Bob");
20 u2.set_email();
21 u2.change_password();
22 user_lst.push_back(u2);
23 cout << endl;
24
25 User u3("Hellen");
26 u3.set_email();
27 u3.change_password();
28 user_lst.push_back(u3);
29 cout << endl;
30
31 cout << "There are " << user_lst.size() << " users. they are: " << endl;
32 for (auto& i : user_lst) {
33 i.display();
34 cout << endl;
35 }
36 }
37
38 int main() {
39 test();
40 }
实验任务六
1 #pragma once
2 class Date
3 {
4 private:
5 int year;
6 int month;
7 int day;
8 int totalDays;
9 public:
10 Date(int year, int month, int day);
11 int getYear()const { return year; }
12 int getMonth() const { return month; }
13 int getDay()const { return day; }
14 int getMaxDay()const;
15 bool isLeapYear()const
16 {
17 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
18 }
19 void show()const;
20 int distance(const Date& date)const
21 {
22 return totalDays - date.totalDays;
23 }
24 };
date.h
1 #include"date.h"
2 #include<iostream>
3 #include<cstdlib>
4
5 using namespace std;
6
7 namespace
8 {
9 const int DAYS_BEFORE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 };
10 }
11 Date::Date(int year, int month, int day) :year(year), month(month), day(day)
12 {
13 if (day <= 0 || day > getMaxDay())
14 {
15 cout << "Invalid date: ";
16 show();
17 cout << endl;
18 exit(1);
19 }
20 int years = year - 1;
21 totalDays = year * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
22 if (isLeapYear() && month > 2) totalDays++;
23 }
24 int Date::getMaxDay()const
25 {
26 if (isLeapYear() && month == 2)
27 return 29;
28 else
29 return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
30 }
31 void Date::show() const
32 {
33 cout << getYear() << "-" << getMonth() << "-" << getDay();
34 }
date.cpp
1 #pragma once
2 #include"date.h"
3 #include<string>
4
5 class SavingsAccount
6 {
7 private:
8 std::string id;
9 double balance;
10 double rate;
11 Date lastDate;
12 double accumulation;
13 static double total;
14 void record(const Date& date, double amount, const std::string& desc);
15
16 void error(const std::string& msg)const;
17
18 double accumulate(const Date& date) const
19 {
20 return accumulation + balance * date.distance(lastDate);
21
22 }
23 public:
24 SavingsAccount(const Date& date, const std::string& id, double rate);
25
26 const std::string& getId() const { return id; }
27 double getBalance() const { return balance; }
28
29 double getRate() const { return rate; }
30
31 static double getTotal() { return total; }
32
33 void deposit(const Date& date, double amount, const std::string& desc);
34
35 void withdraw(const Date& date, double amount, const std::string& desc);
36
37 void settle(const Date& date);
38
39 void show() const;
40 };
account.h
1 #include "account.h"
2 #include<cmath>
3 #include<iostream>
4
5 using namespace std;
6
7 double SavingsAccount::total = 0;
8
9 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) : id(id), balance(0), rate(rate), lastDate(date), accumulation(0)
10 {
11 date.show();
12 cout << "\t#" << id << " created" << endl;
13 }
14
15 void SavingsAccount::record(const Date& date, double amount, const string& desc)
16 {
17 accumulation = accumulate(date);
18
19 lastDate = date;
20
21 amount = floor(amount * 100 + 0.5) / 100; //保留小数点后两位
22 balance += amount;
23 total += amount;
24 date.show();
25
26 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
27
28 }
29 void SavingsAccount::error(const string& msg)const
30 {
31 cout << "Error(#" << id << "):" << msg << endl;
32
33 }
34
35 void SavingsAccount::deposit(const Date& date, double amount, const string& desc)
36 {
37 record(date, amount, desc);
38
39 }
40
41 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc)
42 {
43 if (amount > getBalance())
44 error("not enough money");
45 else
46 record(date, -amount, desc);
47
48 }
49
50 void SavingsAccount::settle(const Date& date)
51 {
52
53 double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1)); //计算年息
54
55 if (interest != 0)
56
57 record(date, interest, "interest");
58
59 accumulation = 0;
60
61 }
62
63 void SavingsAccount::show() const
64 {
65 cout << id << "\tBalance:" << balance;
66 }
account.cpp
1 #include"account.h"
2 #include<iostream>
3
4 using namespace std;
5
6 int main()
7 {
8 Date date(2008, 11, 1);
9
10 SavingsAccount accounts[] =
11 {
12 SavingsAccount(date, "03755217", 0.015),
13 SavingsAccount(date, "02342342", 0.015)
14 };
15 const int n = sizeof(accounts) / sizeof(SavingsAccount);
16
17 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");
18 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
19 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");
20 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
21
22 cout << endl;
23 for (int i = 0; i < n; i++)
24 {
25 accounts[i].settle(Date(2009, 1, 1));
26 accounts[i].show();
27 cout << endl;
28 }
29 cout << "Total: " << SavingsAccount::getTotal() << endl;
30 return 0;
31 }
task6.cpp
标签：std,const,cout,对象,编程,int,实验,include,string From： https://www.cnblogs.com/zth1027/p/18536346