实验三
task1
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:
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 }
定义了两个类，使用类标准库中的vector和string，button中有string，window中有button、string、vector；我认为未设置成const或者inline中的无可添加；构建一个长度为40的字符串。
实验截图：
task2
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 }
截图：
问题1：第一行构建一个int类型的，长度为5的，值都为42的动态数组v1；第二行将v1复制给v2；第三行将v1的第一个数据改为-999。
问题2：第一行构建int类型的二位动态数组v1，第二行将v1复制给v2，第三行给动态数组第一行末尾添加一个-999。
问题3：第一行将v1的第一行复制给t1，第二行输出t1的最后一个值，第三行将v2的第一行复制给t2，第四行输出t2的最后一个值。
问题4：深复制，需要一个const。
task3
代码：
vectorlnt.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:
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 }
截图：
问题1：深复制
问题2：不可以运行，传进去的形参有被修改的风险。
task4
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 // 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 Matrix::Matrix(int n,int m):lines{n},cols{m}{ 37 ptr=new double[n*m]; 38 } 39 40 Matrix::Matrix(int n):lines{n},cols{n}{ 41 ptr=new double[n*n]; 42 } 43 44 Matrix::~Matrix(){ 45 delete []ptr; 46 } 47 48 Matrix::Matrix(const Matrix &x):lines{x.lines},cols{x.cols}{ 49 ptr=new double[lines*cols]; 50 for(int i=0;i<lines*cols;++i){ 51 ptr[i]=x.ptr[i]; 52 } 53 54 } 55 56 const double& Matrix::at(int i,int j) const{ 57 assert(i>=0&&i<lines&&j>=0&&j<cols); 58 return ptr[i*cols+j]; 59 } 60 61 double& Matrix::at(int i,int j){ 62 assert(i>=0&&i<lines&&j>=0&&j<cols); 63 return ptr[i*cols+j]; 64 } 65 66 void Matrix::set(const double *pvalue){ 67 for(int i=0;i<lines*cols;++i){ 68 ptr[i]=pvalue[i]; 69 } 70 } 71 72 void Matrix::clear(){ 73 for(int i=0;i<lines*cols;++i){ 74 ptr[i]=0; 75 } 76 } 77 78 int Matrix::get_lines()const{ 79 return lines; 80 } 81 82 int Matrix::get_cols()const{ 83 return cols; 84 } 85 86 void Matrix::display()const{ 87 int i=0,j=0; 88 for(i;i<lines;++i){ 89 for(j;j<cols;++j){ 90 cout<<ptr[i*cols+j]<<" "; 91 } 92 cout<<endl; 93 } 94 }
task.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, 2, 3, 4, 5, 6, 7, 8, 9}; 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 }
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task5
代码：
user.hpp
1 #pragma once 2 3 #include<iostream> 4 #include<vector> 5 6 using namespace std; 7 8 class User { 9 public: 10 User(const string& name1, const string& password1="123456", const string& email1=""); 11 void set_email(); 12 void change_password(); 13 void display() const; 14 private: 15 string name; 16 string password; 17 string email; 18 }; 19 User::User(const string& name1, const string& password1, const string& email1) :name { name1 }, password { password1 }, email { email1 } { 20 } 21 void User::set_email() { 22 cout << "Enter email address: "; 23 string emaill; 24 cin >> emaill; 25 while (1) { 26 if (emaill.find('@') != string::npos) { 27 email = emaill; 28 cout << "email is set successfully..." << endl; 29 break; 30 } else { 31 cout << "illegal email.Please re-enter email: "; 32 cin >> emaill; 33 cout; 34 } 35 } 36 } 37 void User::change_password() { 38 cout << "Enter old password: "; 39 string password1; 40 cin >> password1; 41 int cnts = 1; 42 while (cnts < 3) { 43 if (password1 == password) { 44 cout << "new password: "; 45 cin >> password1; 46 password = password1; 47 cout << "new password is set successfully..." ; 48 break; 49 } else { 50 cout << "password input error. Please re-enter agagin"; 51 cin >> password1; 52 cnts++; 53 } 54 } 55 if (cnts == 3) cout << "password input error.Please try after a while" << endl;; 56 } 57 void User::display()const { 58 cout << "name: " << name << endl; 59 cout << "pass: " << password << endl; 60 cout << "email: " << email << endl; 61 }
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", "Alice@hotmail.com"); 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 }
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task6
代码：
date.hpp:
1 #pragma once 2 3 #include<iostream> 4 #include<cstdlib> 5 6 using namespace std; 7 class Date { 8 private: 9 int year; 10 int month; 11 int day; 12 int totalDays; 13 public: 14 Date(int year, int month, int day); 15 int getYear()const { 16 return year; 17 } 18 int getMonth()const { 19 return month; 20 } 21 int getDay()const { 22 return day; 23 } 24 int getMaxDay()const; 25 bool isLeapYear()const { 26 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0; 27 } 28 void show() const; 29 int distance(const Date& date)const { 30 return totalDays - date.totalDays; 31 } 32 }; 33 namespace { 34 const int DAYS_BEFIRE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304 ,334,365 }; 35 } 36 Date::Date(int year, int month, int day) :year(year), month(month), day(day) { 37 if (day <= 0 || day > getMaxDay()) { 38 cout << "Invalid date: "; 39 show(); 40 cout << endl; 41 exit(1); 42 } 43 int years = year - 1; 44 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFIRE_MONTH[month - 1] + day; 45 if (isLeapYear() && month > 2) totalDays++; 46 } 47 int Date::getMaxDay()const { 48 if (isLeapYear() &&month == 2) 49 return 29; 50 else return DAYS_BEFIRE_MONTH[month] - DAYS_BEFIRE_MONTH[month - 1]; 51 } 52 void Date::show()const { 53 cout << getYear() << "-" << getMonth() << "-" << getDay(); 54 }
account.hpp
1 #pragma once 2 3 #include"date.hpp" 4 #include<string> 5 #include<cmath> 6 #include<iostream> 7 8 using namespace std; 9 10 class SavingsAccount { 11 private: 12 string id; 13 double balance; 14 double rate; 15 Date lastDate; 16 double accumulation; 17 static double total; 18 void record(const Date& date, double amount, const string& desc); 19 void error(const string& msg) const; 20 double accumulate(const Date& date)const { 21 return accumulation + balance * date.distance(lastDate); 22 } 23 public: 24 SavingsAccount(const Date& date, const string& id, double rate); 25 const string& getId()const { 26 return id; 27 } 28 double getBalance()const { 29 return balance; 30 } 31 double getRate()const { 32 return rate; 33 } 34 static double getTotal() { 35 return total; 36 } 37 void deposit(const Date& date, double amount, const string& desc); 38 void withdraw(const Date& date, double amount, const string& desc); 39 void settle(const Date& date); 40 void show() const; 41 }; 42 double SavingsAccount::total = 0; 43 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) : 44 id(id), balance(0), rate(rate), lastDate(date), accumulation(0) { 45 date.show(); 46 cout << "\t#" << id << "created" << endl; 47 } 48 void SavingsAccount::record(const Date& date, double amount, const string& desc) { 49 accumulation = accumulate(date); 50 lastDate = date; 51 amount = floor(amount * 100 + 0.5) / 100; 52 balance += amount; 53 total += amount; 54 date.show(); 55 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl; 56 } 57 void SavingsAccount::error(const string& msg) const { 58 cout << "Error(#" << id << "):" << msg << endl; 59 } 60 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) { 61 record(date, amount, desc); 62 } 63 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) { 64 if (amount > getBalance()) 65 error("not enough money"); 66 else 67 record(date, -amount, desc); 68 } 69 void SavingsAccount::settle(const Date& date) { 70 double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1)); 71 if (interest != 0) record( date,interest,"interest" ); 72 accumulation = 0; 73 } 74 void SavingsAccount::show()const { 75 cout << id << "\tBalance: " << balance; 76 }
task6.cpp
1 #include"account.hpp" 2 #include<iostream> 3 using namespace std; 4 int main() { 5 Date date { 2008,11,1 }; 6 SavingsAccount accounts[] = { 7 SavingsAccount(date,"03755217",0.015), 8 SavingsAccount(date,"02342342",0.015) 9 }; 10 const int n = sizeof(accounts) / sizeof(SavingsAccount); 11 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary"); 12 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323"); 13 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary"); 14 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop"); 15 cout << endl; 16 for (int i = 0; i < n; i++) { 17 accounts[i].settle(Date(2009, 1, 1)); 18 accounts[i].show(); 19 cout << endl; 20 } 21 cout << "Total: " << SavingsAccount::getTotal() << endl; 22 return 0; 23 }
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