实验三 c++
实验任务一
源代码
button.hpp
1 #pragma once 2 3 #include<iostream> 4 #include<string> 5 6 using std::string; 7 using std::cout; 8 9 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 inline string Button::get_label()const{ 22 return label; 23 } 24 25 void Button::click() { 26 cout<<"Button '"<<label<<"' clicked\n"; 27 }
window.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 }
test.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 }
运行结果截图
问题1.自定义了两个类，使用了标准库的vetor，string。Button和Window是组合关系，vector和Window是组合关系，string和Window是组合关系
问题2.不需要，他们在调用时，不会改变成员数据
问题3.功能是打印40个*
实验任务二
源代码
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 }
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问题1.第一行，创建一个长度为5，元素都是42的数组v1，第二行是复制v1的数组到v2，第三行是将v1的第一个元素改为-999。
问题2.第一行创建一个二维数组v1，共有两行，前三个元素一行，后四个元素一行。第二行复制v1到数组v2。第三行在v1的第一行中添加元素-999
问题3.将v1的第一行赋值给t1，之后输出t1的最后一个元素，再将v2的第一行赋值给t2，输出t2的最后一个元素
问题4.①深复制②不需要
实验任务三
源代码
vectorInt.hpp
1 #pragma once 2 3 #include <iostream> 4 #include <cassert> 5 6 using std::cout; 7 using std::endl; 8 9 class vectorInt { 10 public: 11 vectorInt(int n); 12 vectorInt(int n, int value); 13 vectorInt(const vectorInt& vi); 14 ~vectorInt(); 15 16 int& at(int index); 17 const int& at(int index)const; 18 vectorInt& assign(const vectorInt& v); 19 int get_size()const; 20 21 private: 22 int size; 23 int* ptr; 24 }; 25 26 vectorInt::vectorInt(int n) :size{ n }, ptr{ new int[size] } { 27 } 28 29 vectorInt::vectorInt(int n, int value) :size{ n }, ptr{ new int[size] } { 30 for (auto i = 0; i < size; i++) { 31 ptr[i] = value; 32 } 33 } 34 35 vectorInt::vectorInt(const vectorInt& vi) :size{ vi.size }, ptr{ new int[size] } { 36 for (auto i = 0; i < size; i++) { 37 ptr[i] = vi.ptr[i]; 38 } 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; 59 60 size = v.size; 61 ptr = new int[size]; 62 for (int i = 0; i < size; i++) 63 ptr[i] = v.ptr[i]; 64 65 return *this; 66 } 67 68 int vectorInt::get_size()const { 69 return size; 70 71 }
test3.cpp
1 #include"vecterint.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 void test1() { 14 int n; 15 cout << "Enter n: "; 16 cin >> n; 17 18 vectorInt x1(n); 19 for (auto i = 0; i < n; i++) 20 x1.at(i) = i * i; 21 cout << "x1: "; output(x1); 22 23 vectorInt x2(n, 42); 24 vectorInt x3(x2); 25 x2.at(0) = -999; 26 cout << "x2: "; output(x2); 27 cout << "x3: "; output(x3); 28 } 29 30 void test2() { 31 const vectorInt x(5, 42); 32 vectorInt y(10, 0); 33 34 cout << "y: "; output(y); 35 y.assign(x); 36 cout << "y: "; output(y); 37 38 cout << "x.at(0)= " << x.at(0) << endl; 39 cout << "y.at(0)= " << y.at(0) << endl; 40 41 } 42 43 int main() { 44 cout << "test1:\n"; 45 test1(); 46 cout << "test2:\n"; 47 test2(); 48 }
运行结果截图
问题1.深复制
问题2.不能正常运行，因为改成int后，将返回元素值的形参，无法更改其值。存在。因为去掉const后，后返回int&类型，而调用at这个接口的const型变量将有可能被改变值
问题3.可以，因为调用assign接口，并未改变对象成员数据的值，仅作复制操作，所以可以更改。
实验任务四
源代码
matrix.hpp
1 #pragma once 2 #include <iostream> 3 #include <cassert> 4 using std::cout; 5 using std::endl; 6 // 类Matrix的声明 7 class Matrix { 8 public: 9 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵, 初始值为value 10 Matrix(int n);// 构造函数，构造一个n*n的矩阵, 初始值为value 11 Matrix(const Matrix& x);// 复制构造函数， 使用已有的矩阵X构造 12 ~Matrix(); 13 void set(const double* pvalue);// 用pvalue指向的连续内存块数据按行为矩阵赋值 14 void clear();// 把矩阵对象的值置0 15 16 const double& at(int i, int j) const;// 返回矩阵对象索引(i,j)的元素const引用 17 double& at(int i, int j);// 返回矩阵对象索引(i,j)的元素引用 18 19 int get_lines() const;// 返回矩阵对象行数 20 int get_cols() const;// 返回矩阵对象列数 21 void display() const;// 按行显示矩阵对象元素值 22 private: 23 int lines;// 矩阵对象内元素行数 24 int cols;// 矩阵对象内元素列数 25 double* ptr; 26 }; 27 // 类Matrix的实现：待补足 28 Matrix::Matrix(int n, int m) :lines{ n }, cols{ m }, ptr{ new double[n * m ]} {} 29 Matrix::Matrix(int n):lines{n},cols{n},ptr{new double [n*n]}{} 30 Matrix::Matrix(const Matrix& x) :ptr{new double [x.lines*x.cols]} { 31 lines = x.lines; 32 cols = x.cols; 33 for (auto i = 0; i < lines * cols; i++) 34 ptr[i] = x.ptr[i]; 35 } 36 Matrix::~Matrix() { delete[]ptr; } 37 void Matrix::set(const double* pvalue) { 38 for (auto i = 0; i < lines * cols; i++) { 39 ptr[i] = pvalue[i]; 40 } 41 } 42 void Matrix::clear() { 43 for (auto i = 0; i < lines * cols; i++) { 44 ptr[i] = 0; 45 } 46 } 47 48 const double& Matrix::at(int i, int j)const { 49 assert(i * j >= 0 && i * j < lines * cols); 50 return ptr[i*j+j]; 51 } 52 53 double& Matrix::at(int i, int j) { 54 assert(i * j >= 0 && i * j < lines * cols); 55 return ptr[i*j+j]; 56 } 57 58 int Matrix::get_lines()const { 59 return lines; 60 } 61 62 int Matrix::get_cols()const { 63 return cols; 64 } 65 66 void Matrix::display()const { 67 for (auto i = 0; i < lines*cols; i++) { 68 cout << ptr[i] << ", "; 69 if((i+1)%cols==0) 70 cout << "\b\b \n"; 71 } 72 cout << endl; 73 }
task4.cpp
1 #include "matrix.hpp" 2 #include <iostream> 3 #include <cassert> 4 using std::cin; 5 using std::cout; 6 using std::endl; 7 const int N = 1000; 8 // 输出矩阵对象索引为index所在行的所有元素 9 10 void output(const Matrix& m, int index) { 11 assert(index >= 0 && index < m.get_lines()); 12 for (auto j = 0; j < m.get_cols(); ++j) 13 cout << m.at(index, j) << ", "; 14 cout << "\b\b \n"; 15 } 16 17 void test1() { 18 double x[1000] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }; 19 int n, m; 20 cout << "Enter n and m: "; 21 cin >> n >> m; 22 Matrix m1(n, m);// 创建矩阵对象m1, 大小n×m 23 m1.set(x);// 用一维数组x的值按行为矩阵m1赋值 24 Matrix m2(m, n);// 创建矩阵对象m1, 大小m×n 25 m2.set(x);// 用一维数组x的值按行为矩阵m1赋值 26 Matrix m3(2);// 创建一个2×2矩阵对象 27 m3.set(x);// 用一维数组x的值按行为矩阵m4赋值 28 cout << "矩阵对象m1: \n";m1.display();cout << endl; 29 cout << "矩阵对象m2: \n";m2.display();cout << endl; 30 cout << "矩阵对象m3: \n";m3.display();cout << endl; 31 } 32 33 void test2() { 34 Matrix m1(2, 3); 35 m1.clear(); 36 37 const Matrix m2(m1); 38 m1.at(0, 0) = -999; 39 cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl; 40 cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl; 41 cout << "矩阵对象m1第0行: "; output(m1, 0); 42 cout << "矩阵对象m2第0行: "; output(m2, 0); 43 } 44 int main() { 45 cout << "测试1: \n"; 46 test1(); 47 cout << "测试2: \n"; 48 test2(); 49 }
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实验任务五
源代码
User.hpp
1 #pragma once 2 3 #include<iostream> 4 #include<iomanip> 5 #include<string> 6 #include<algorithm> 7 8 using namespace std; 9 10 class User { 11 private: 12 string name,password,email; 13 public: 14 User(string N, string P = "123456", string E = ""); 15 ~User(){} 16 17 void set_email(); 18 void change_password(); 19 void display(); 20 }; 21 22 User::User(string N, string P, string E):name{ N }, password{ P }, email{ E } {} 23 24 void User::set_email() { 25 cout << "Enter email address: "; 26 while (1) { 27 cin >> email; 28 size_t index = email.find("@"); 29 if (index != string::npos) { 30 cout << "email is set successfully..." << endl; 31 break; 32 } 33 cout << "illegal email. Please re-enter email: "; 34 } 35 } 36 37 void User::change_password() { 38 string s; 39 cout << "Enter old password: "; 40 cin >> s; 41 for (int i = 0; i < 3; i++) { 42 if (s == password) { 43 cout << "Enter new password: "; 44 cin >> password; 45 cout<<"new password is set successfully..."<<endl; 46 break; 47 } 48 if (i == 2) { 49 cout << "password input error. Please try after a while." << endl;; 50 break; 51 } 52 cout << "password input error. Please re-enter angain: "; 53 cin >> s; 54 } 55 } 56 57 void User::display() { 58 size_t n = password.length(); 59 string s(n, '*'); 60 cout << "name: " << name << endl 61 << "pass: " << s << endl 62 << "email: " << email << endl; 63 }
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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实验任务六
源代码
date.h
1 #pragma once 2 3 class Date { 4 private: 5 int year; 6 int month; 7 int day; 8 int totalDays; 9 public: 10 Date(int year, int maonth, 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 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0; 17 } 18 void show()const; 19 int diatance(const Date& date)const { 20 return totalDays - date.totalDays; 21 } 22 };
date.cpp
1 #include"date.h" 2 #include<iostream> 3 #include<cstdlib> 4 using namespace std; 5 namespace { 6 const int DATS_BEFORE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304,334,365 }; 7 } 8 9 Date::Date(int year, int month, int day) :year{ year }, month{ month }, day{ day } { 10 if (day <= 0 || day > getMaxDay()) { 11 cout << "Invalid date: "; 12 show(); 13 exit(1); 14 } 15 int years = year - 1; 16 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DATS_BEFORE_MONTH[month - 1] + day; 17 if (isLeapYear() && month > 2)totalDays++; 18 } 19 20 int Date::getMaxDay()const { 21 if (isLeapYear() && month == 2) 22 return 29; 23 else 24 return DATS_BEFORE_MONTH[month] - DATS_BEFORE_MONTH[month - 1]; 25 } 26 27 void Date::show()const { 28 cout << getYear() << "-" << getMonth() << "-" << getDay(); 29 }
account.h
1 #pragma once 2 #include"date.h" 3 #include<string> 4 5 class SavingAccount { 6 private: 7 std::string id; 8 double balance; 9 double rate; 10 Date lastDate; 11 double accumulation; 12 static double total; 13 14 void record(const Date& date, double amount, const std::string& desc); 15 void error(const std::string& msg)const; 16 double accumulate(const Date& date)const { 17 return accumulation + balance * date.diatance(lastDate); 18 } 19 20 public: 21 SavingAccount(const Date& date, const std::string& id, double rate); 22 const std::string& getId()const { return id; } 23 double getBalance()const { return balance;} 24 double getRate()const { return rate; } 25 static double getTotal() { return total; } 26 27 void deposit(const Date& date, double amount, const std::string& desc); 28 void withdraw(const Date& date, double amount, const std::string& desc); 29 30 void settle(const Date& date); 31 void show()const; 32 };
account.cpp
1 #include"account.h" 2 #include<cmath> 3 #include<iostream> 4 using namespace std; 5 double SavingAccount::total = 0; 6 7 SavingAccount::SavingAccount(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 SavingAccount::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 void SavingAccount::error(const string& msg)const { 22 cout << "Error(#" << id << "): " << msg << endl; 23 } 24 25 26 void SavingAccount::deposit(const Date& date, double amount, const string& desc) { 27 record(date, amount, desc); 28 } 29 void SavingAccount::withdraw(const Date& date, double amount, const string& desc) { 30 if (amount > getBalance()) 31 error("not enough money"); 32 else 33 record(date, -amount, desc); 34 } 35 36 void SavingAccount::settle(const Date& date) { 37 double interest = accumulate(date) * rate / date.diatance(Date(date.getYear() - 1, 1, 1)); 38 if (interest != 0) 39 record(date, interest, "interest"); 40 accumulation = 0; 41 42 } 43 void SavingAccount::show()const { 44 cout << id << "\tBalance:" << balance; 45 }
6_25.cpp
1 #include"account.h" 2 #include<iostream> 3 using namespace std; 4 int main() { 5 Date date(2008, 11, 1); 6 SavingAccount accounts[] = { 7 SavingAccount(date,"03755217",0.015), 8 SavingAccount(date,"02342342",0.015) 9 }; 10 const int n = sizeof(accounts) / sizeof(SavingAccount); 11 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary"); 12 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323"); 13 14 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary"); 15 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a lappot"); 16 17 cout << endl; 18 for (int i = 0; i < n; i++) { 19 accounts[i].settle(Date(2009, 1, 1)); 20 accounts[i].show(); 21 cout << endl; 22 } 23 cout << "Total: " << SavingAccount::getTotal() << endl; 24 return 0; 25 }
运行结果截图
