实验任务1：
button.hpp
#pragma once#include <iostream> #include <string>using std::string; using std::cout;// 按钮类 class Button { public:Button(const string &text);string get_label() const;void click();private:string label; };Button::Button(const string &text): label{text} { }inline string Button::get_label() const {return label; }void Button::click() {cout << "Button '" << label << "' clicked\n"; }
window.hpp
#pragma once #include "button.hpp" #include <vector> #include <iostream>using std::vector; using std::cout; using std::endl;// 窗口类 class Window{ public:Window(const string &win_title);void display() const;void close();void add_button(const string &label);private:string title;vector<Button> buttons; };Window::Window(const string &win_title): title{win_title} {buttons.push_back(Button("close")); }inline void Window::display() const {string s(40, '*');cout << s << endl;cout << "window title: " << title << endl;cout << "It has " << buttons.size() << " buttons: " << endl;for(const auto &i: buttons)cout << i.get_label() << " button" << endl;cout << s << endl; }void Window::close() {cout << "close window '" << title << "'" << endl;buttons.at(0).click(); }void Window::add_button(const string &label) {buttons.push_back(Button(label)); }
task1.cpp
#include "window.hpp" #include <iostream>using std::cout; using std::cin;void test() {Window w1("new window");w1.add_button("maximize");w1.display();w1.close(); }int main() {cout << "用组合类模拟简单GUI:\n";test(); }
问题1：自定义了button类和window类；使用了标准库中的string、vector、iostream类；window类与button类存在组合关系
问题2：不适合， 因为它们被调用时候不会改变数据，不需要加const，而且被调用的次数不多，不需要加inline
问题3：定义一个字符串s，它由40个*组成
实验任务2：
task2.cpp
#include <iostream> #include <vector>using namespace std;void output1(const vector<int> &v) {for(auto &i: v)cout << i << ", ";cout << "\b\b \n"; }void output2(const vector<vector<int>> v) {for(auto &i: v) {for(auto &j: i)cout << j << ", ";cout << "\b\b \n";} }void test1() {vector<int> v1(5, 42);const vector<int> v2(v1);v1.at(0) = -999;cout << "v1: "; output1(v1);cout << "v2: "; output1(v2);cout << "v1.at(0) = " << v1.at(0) << endl;cout << "v2.at(0) = " << v2.at(0) << endl; }void test2() {vector<vector<int>> v1{{1, 2, 3}, {4, 5, 6, 7}};const vector<vector<int>> v2(v1);v1.at(0).push_back(-999);cout << "v1: \n"; output2(v1);cout << "v2: \n"; output2(v2);vector<int> t1 = v1.at(0);cout << t1.at(t1.size()-1) << endl;const vector<int> t2 = v2.at(0);cout << t2.at(t2.size()-1) << endl; }int main() {cout << "测试1:\n";test1();cout << "\n测试2:\n";test2(); }
问题1：先创建了一个名为v1的vector，包含5跟都是42的元素，然后创建一个名为v2的vector，并用v1来将其初始化，最后将v1的第一个元素改成了-999.
问题2：先创建了一个名为v1的二维vector，然后创建了一个名为v2的二维vector，并用v1来初始化，且因为v2前的const所以v2的值不能改变，最后在v1中的第一个元素“1，2，3”后面添加了一个-999.
问题3：创建了一个名为t1的的vector，并用v1的第一个元素来将其初始化，然后输出t1的最后一个元素的值；创建了一个名为t2的vector，并用v2的第一个元素来将其初始化，然后输出t2的最后一个元素的值，并且因为t2前的const所以t2不能被修改
问题4:
1.深复制
2.需要
实验任务3：
vocterInt.hpp
#pragma once#include <iostream> #include <cassert>using std::cout; using std::endl;// 动态int数组对象类 class vectorInt{ public:vectorInt(int n);vectorInt(int n, int value);vectorInt(const vectorInt &vi);~vectorInt();int& at(int index);const int& at(int index) const;vectorInt& assign(const vectorInt &v);int get_size() const;private:int size;int *ptr; // ptr指向包含size个int的数组 };vectorInt::vectorInt(int n): size{n}, ptr{new int[size]} { }vectorInt::vectorInt(int n, int value): size{n}, ptr{new int[size]} {for(auto i = 0; i < size; ++i)ptr[i] = value; }vectorInt::vectorInt(const vectorInt &vi): size{vi.size}, ptr{new int[size]} {for(auto i = 0; i < size; ++i)ptr[i] = vi.ptr[i]; }vectorInt::~vectorInt() {delete [] ptr; }const int& vectorInt::at(int index) const {assert(index >= 0 && index < size);return ptr[index]; }int& vectorInt::at(int index) {assert(index >= 0 && index < size);return ptr[index]; }vectorInt& vectorInt::assign(const vectorInt &v) { delete[] ptr; // 释放对象中ptr原来指向的资源 size = v.size;ptr = new int[size];for(int i = 0; i < size; ++i)ptr[i] = v.ptr[i];return *this; }int vectorInt::get_size() const {return size; }
task3.cpp
#include "vectorInt.hpp" #include <iostream>using std::cin; using std::cout;void output(const vectorInt &vi) {for(auto i = 0; i < vi.get_size(); ++i)cout << vi.at(i) << ", ";cout << "\b\b \n"; }void test1() {int n;cout << "Enter n: ";cin >> n;vectorInt x1(n);for(auto i = 0; i < n; ++i)x1.at(i) = i*i;cout << "x1: "; output(x1);vectorInt x2(n, 42);vectorInt x3(x2);x2.at(0) = -999;cout << "x2: "; output(x2);cout << "x3: "; output(x3); }void test2() {const vectorInt x(5, 42);vectorInt y(10, 0);cout << "y: "; output(y);y.assign(x);cout << "y: "; output(y);cout << "x.at(0) = " << x.at(0) << endl;cout << "y.at(0) = " << y.at(0) << endl; }int main() {cout << "测试1: \n";test1();cout << "\n测试2: \n";test2(); }
问题1：深复制
问题2：不能，因为int&存储的是一个int类型的数据的地址，允许修改元素值，而int存储的是int类型数据的副本，无法修改原来的元素值；存在安全隐患，因为可能会改变元素的值。
问题3：可以，不过会额外创建一个vectorInt，需要额外的空间。
实验任务4：
matrix.hpp
#pragma once#include <iostream> #include <cassert>using std::cout; using std::endl;// 类Matrix的声明 class Matrix { public:Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵, 初始值为valueMatrix(int n); // 构造函数，构造一个n*n的矩阵, 初始值为valueMatrix(const Matrix &x); // 复制构造函数， 使用已有的矩阵X构造~Matrix();void set(const double *pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值void clear(); // 把矩阵对象的值置0const double& at(int i, int j) const; // 返回矩阵对象索引(i,j)的元素const引用double& at(int i, int j); // 返回矩阵对象索引(i,j)的元素引用int get_lines() const; // 返回矩阵对象行数int get_cols() const; // 返回矩阵对象列数void display() const; // 按行显示矩阵对象元素值private:int lines; // 矩阵对象内元素行数int cols; // 矩阵对象内元素列数double *ptr; };Matrix::Matrix(int n,int m):lines{n},cols{m}{ptr=new double[n*m]; } Matrix::Matrix(int n){ptr=new double[n*n]; }Matrix::Matrix(const Matrix &x):lines{x.lines},cols{x.cols}{ptr=new double[lines*cols];for(int i=0;i<lines*cols;i++)ptr[i]=x.ptr[i]; }Matrix::~Matrix(){delete []ptr; }void Matrix::set(const double* pvalue){for(int i=0;i<lines*cols;i++)ptr[i]=pvalue[i]; }void Matrix::clear(){for(int i=0;i<lines*cols;++i)ptr[i]=0;}const double& Matrix::at(int i,int j)const {return ptr[i*cols+j]; } double& Matrix::at(int i,int j){return ptr[i*cols+j]; } int Matrix::get_lines()const{return lines; } int Matrix::get_cols()const{return cols; } void Matrix::display()const{for(int i=0;i<lines*cols;i++){if((i+1)%cols!=0){cout<<ptr[i]<<" ,";}else{cout<<ptr[i]<<endl;}} }
task4.cpp
#include "matrix.hpp" #include <iostream> #include <cassert>using std::cin; using std::cout; using std::endl;const int N = 1000;// 输出矩阵对象索引为index所在行的所有元素 void output(const Matrix &m, int index) {assert(index >= 0 && index < m.get_lines());for(auto j = 0; j < m.get_cols(); ++j)cout << m.at(index, j) << ", ";cout << "\b\b \n"; }void test1() {double x[1000] = {1, 2, 3, 4, 5, 6, 7, 8, 9};int n, m;cout << "Enter n and m: ";cin >> n >> m;Matrix m1(n, m); // 创建矩阵对象m1, 大小n×mm1.set(x); // 用一维数组x的值按行为矩阵m1赋值 Matrix m2(m, n); // 创建矩阵对象m1, 大小m×nm2.set(x); // 用一维数组x的值按行为矩阵m1赋值 Matrix m3(2); // 创建一个2×2矩阵对象m3.set(x); // 用一维数组x的值按行为矩阵m4赋值 cout << "矩阵对象m1: \n"; m1.display(); cout << endl;cout << "矩阵对象m2: \n"; m2.display(); cout << endl;cout << "矩阵对象m3: \n"; m3.display(); cout << endl; }void test2() {Matrix m1(2, 3);m1.clear();const Matrix m2(m1);m1.at(0, 0) = -999;cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;cout << "矩阵对象m1第0行: "; output(m1, 0);cout << "矩阵对象m2第0行: "; output(m2, 0); }int main() {cout << "测试1: \n";test1();cout << "测试2: \n";test2(); }
实验任务5：
user.cpp
#pragma once#include<iostream> #include<string> #include<vector>using std::cin; using std::cout; using std::endl; using std::vector; using std::string;class User{public:User(string a, string b= "123456", string c= "");void set_email();void change_password();void display();private:string name,email,password;};User::User(string a, string b, string c):name {a}, password {b}, email {c} { }void User::set_email() {cout << "Enter email address: ";int a=0;string newemail;while(!a) {cin >> newemail;for (char c: newemail) {if (c == '@') a=1; }if(a==0)cout << "illegal email.Please re-enter email: "; else {email=newemail;cout << "email is set successfully..." << endl;} } }void User::change_password() {string t;cout << "Enter old password:" << endl;int c = 0;while(c < 3) {cin >> t;if(password==t) {cout << "Enter new password:" << endl;cin >> password;cout << "new password is set successfully...";break;} else {cout << "password input error. Please re-enter angain:" << endl;cin.clear();}++c;}if(c == 3) {cout << "password input error. Please try after a while.";} }void User::display() {cout << "name: " << name << endl;cout << "pass: ";for(int i = 0; i < password.size(); i++) {cout << "*";}cout << endl;cout << "eamil: " << email << endl; }
task5.cpp
#include "user.hpp" #include <iostream> #include <vector> #include <string>using std::cin; using std::cout; using std::endl; using std::vector; using std::string;void test() {vector<User> user_lst;User u1("Alice", "2024113", "Alice@hotmail.com");user_lst.push_back(u1);cout << endl;User u2("Bob");u2.set_email();u2.change_password();user_lst.push_back(u2);cout << endl;User u3("Hellen");u3.set_email();u3.change_password();user_lst.push_back(u3);cout << endl;cout << "There are " << user_lst.size() << " users. they are: " << endl;for(auto &i: user_lst) {i.display();cout << endl;} }int main() {test(); }
实验任务6：
date.h
#ifndef __DATE_H__ #define __DATE_H__ class Date {private:int year,month,day,totalDays;public:Date(int year,int month,int day);int getYear()const {return year;}int getMonth()const {return month;}int getDay() const {return day;}int getMaxDay() const;bool isLeapYear()const {return year%4==0 && year%100!=0 ||year%400==0;}void show()const;int distance(const Date &date)const {return totalDays-date.totalDays;}}; #endif / / _DATE_H__
date.cpp
#include "date.h" #include <iostream> #include <cstdlib> using namespace std; namespace {const int DAYS_BEFORE_MONTH[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }; } Date::Date(int year, int month, int day) : year(year), month(month), day(day) {if (day <= 0 || day > getMaxDay()) {cout << "Invalid date:";show();cout << endl;exit(1);}int years = year - 1;totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;if (isLeapYear() && month > 2) totalDays++; } int Date::getMaxDay()const {if (isLeapYear() && month == 2)return 29;elsereturn DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1]; } void Date::show() const {cout << getYear() << " - " << getMonth() << " - " << getDay(); }
account.h
#ifndef __ACCOUNT_H__ #define __ACCOUNT_H__ #include "date.h" #include <string> class SavingsAccount {private:std::string id;double balance,rate,accumulation;Date lastDate;static double total;void record(const Date& date, double amount, const std::string& desc);void error(const std::string& msg) const;double accumulate(const Date& date) const {return accumulation + balance * date.distance(lastDate);}public:SavingsAccount(const Date& date, const std::string& id, double rate);const std::string& getId() const {return id;}double getBalance() const {return balance;}double getRate() const {return rate;}static double getTotal() {return total;}void deposit(const Date& date, double amount, const std::string& desc);void withdraw(const Date& date, double amount, const std::string& desc);void settle(const Date& date);void show() const; }; #endif
account.cpp
#include "account.h" #include <cmath> #include <iostream> using namespace std; double SavingsAccount::total = 0; SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {date.show();cout << "\t#" << id << "created" << endl; } void SavingsAccount::record(const Date& date, double amount, const string& desc) {accumulation = accumulate(date);lastDate = date;amount = floor(amount * 100 + 0.5) / 100;balance += amount;total += amount;date.show();cout << "t\#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl; } void SavingsAccount::error(const string& msg) const {cout << "Error(# " << id << " ):" << msg << endl; } void SavingsAccount::deposit(const Date & date, double amount, const string & desc) {record(date, amount, desc); } void SavingsAccount::withdraw(const Date & date, double amount, const string& desc) {if (amount > getBalance())error("not enough money");elserecord(date, -amount, desc); } void SavingsAccount::settle(const Date& date) {double interest = accumulate(date) * rate//计算年息/ date.distance(Date(date.getYear() - 1, 1, 1));if (interest != 0)record(date, interest, "interest");accumulation = 0; } void SavingsAccount::show() const {cout << id << "\tBalance:" << balance; }
task6.cpp
#include "account.h" #include <iostream> using namespace std; int main() {//起始日期Date date(2008, 11, 1);//建立几个账户SavingsAccount accounts[] = {SavingsAccount(date,"03755217",0.015),SavingsAccount(date, "02342342", 0.015)};const int n = sizeof(accounts) / sizeof(SavingsAccount); //账户总数 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");cout << endl;for (int i = 0; i < n; i++) {accounts[i].settle(Date(2009, 1, 1));accounts[i].show();cout << endl;}cout << "Total: " << SavingsAccount::getTotal() << endl;return 0; }
