cpp 实验3

task1

task1
问题一：定义了两个类 Button和window.使用了标准的两个类 string和vector。
问题二: 剩下的函数主要是一些负责输出结果的函数，它们在输出的过程中不会改变对象的值，所以我觉得没有必要加const，当然它们属于简单的输出语句可以设计成内联函数.
问题三：定义一个长度为40且元素都是'*'的string对象s.

 

#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 << "测试2:\n";
    test2();
}

task2
问题一：第一行定义一个长度为5值全为42的整形vector对象v1,第二行使用v1复制构造了一个vector对象v2,第三行对v1的第一个值进行修改.
问题二：第一行定义一个vetcor<int> 类型的vector对象v1,第二行使用复制构造函数定义了一个vector<int> 类型的vetcor对象v2.
问题三：分别使用问题二定义的v1,v2的第一个元素，复制定义两个整形的vector数组，并输出它们的最后一个元素.
问题四:实现的机制是深复制，是.

#pragma once
#include<iostream>
#include<cassert>
using namespace std;
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;
};
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;
    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;
}



#include "标头.h"
#include<iostream>
using namespace std;
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 << "t.at(0)=" << y.at(0) << endl;
}
int main() {
    cout << "测试1: \n";
    test1();
    cout << "测试2:\n";
    test2();
}

task3
问题一:深复制。
问题二：不能正常运行.是，const int& at(int index) const;返回的是引用类型，也就是可以通过它返回值对新的引用变量进行赋值，新的变量在后续操作的过程可能会改变它的值，如果是const对象，它是不允许值发生改变，所以因该加上const.
问题三：可以改成，这段代码的本质就是利用一个const vectorInt进行重新赋值，使不使用引用，对这个过程没有影响，只不过在调用这个函数的时候会有额外内存开销.

#pragma once
#include<iostream>
#include<cassert>
const double n = 0.0;
using namespace std;
class Matrix {
public:
    Matrix(int n, int m);
    Matrix(int n);
    Matrix(const Matrix& x);
    ~Matrix();
    void set(const double* pvalue);
    void clear();
    const double& at(int i, int j) const;
    double& at(int i, int j);
    int get_lines() const;
    int get_cols() const;
    void display() const;
private:
    int lines;
    int clos;
    double* ptr;
};
Matrix::Matrix(int n,int m):lines{n},clos{m}{
    ptr = new double[n*m];
}
Matrix::Matrix(int n) :lines{ n }, clos{ n } {
    ptr = new double[n * n];
}
Matrix::Matrix(const Matrix& x) :lines{ x.lines }, clos{x.clos}{
    ptr = new double[lines * clos];
    for (int i = 0; i < lines * clos; i++) ptr[i] = x.ptr[i];
}
Matrix::~Matrix() {
    delete[] ptr;
}
void Matrix::set(const double* pvalue) {
    for (int i = 0; i < lines * clos; i++)
        ptr[i] = pvalue[i];
}
void Matrix::clear() {
    for (int i = 0; i < lines * clos; i++)
        ptr[i] = 0;
}
const double& Matrix::at(int i, int j) const {
    assert(i >= 0 && i < lines && j >= 0 && j < clos);
    return ptr[i * clos + j];
}
double& Matrix::at(int i, int j) {
    assert(i >= 0 && i < lines && j >= 0 && j < clos);
    return ptr[i * clos + j];
}
int Matrix::get_lines()const {
    return lines;
}
int Matrix::get_cols()const {
    return clos;
}
void Matrix::display() const {
    for (int i = 0; i < lines; i++) {
        for (int j = 0; j < clos; j++)
            cout << ptr[i * clos + j] << ", ";
        cout << "\b\b \n";
    }
}



#include "matrix.h"
#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] = { 9,8,7,6,5,4,3,2,1 };

    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×m
    m1.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×n
    m2.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();
}

#pragma once
#include<iostream>
#include<vector>
using namespace std;
class User {
public:
    User(const string& name1, const string& password1="123456", const string& email1="");
    void set_email();
    void change_password();
    void display() const;
private:
    string name;
    string password;
    string email;
};
User::User(const string& name1, const string& password1, const string& email1) :name{ name1 }, password{ password1 }, email{ email1 } {
}
void User::set_email() {
    cout << "Enter email address: ";
    string emaill;
    cin >> emaill;
    while (1) {
        if (emaill.find('@') != string::npos) {
            email = emaill;
            cout << "email is set successfully..." << endl;
            break;
        }
        else {
            cout << "illegal email.Please re-enter email: ";
            cin >> emaill;
            cout;
        }
    }
}
void User::change_password() {
    cout << "Enter old password: ";
    string password1;
    cin >> password1;
    int cnts = 1;
    while (cnts < 3) {
        if (password1 == password) {
            cout << "new password: ";
            cin >> password1;
            password = password1;
            cout << "new password is set successfully..." ;
            break;
        }
        else {
            cout << "password input error. Please re-enter agagin";
            cin >> password1;
            cnts++;
        }
    }
    if (cnts == 3) cout << "password input error.Please try after a while" << endl;;
}
void User::display()const {
    cout << "name:  " << name << endl;
    cout << "pass:  " << password << endl;
    cout << "email:  " << email << endl;
}




#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();
}

#pragma once
class Date {
private:
    int year;
    int month;
    int day;
    int 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;
    }
};
 


#include"date.h"
#include<iostream>
#include<cstdlib>
using namespace std;
namespace {
    const int DAYS_BEFIRE_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_BEFIRE_MONTH[month - 1] + day;
    if (isLeapYear() && month > 2) totalDays++;
}
int Date::getMaxDay()const {
    if (isLeapYear() &&month == 2)
        return 29;
    else return DAYS_BEFIRE_MONTH[month] - DAYS_BEFIRE_MONTH[month - 1];
}
void Date::show()const {
    cout << getYear() << "-" << getMonth() << "-" << getDay();
}



#pragma once
#include"date.h"
#include<string>
using namespace std;
class SavingsAccount {
private:
    string id;
    double balance;
    double rate;
    Date lastDate;
    double accumulation;
    static double total;
    void record(const Date& date, double amount, const string& desc);
    void error(const string& msg) const;
    double accumulate(const Date& date)const {
        return accumulation + balance * date.distance(lastDate);
    }
public:
    SavingsAccount(const Date& date, const string& id, double rate);
    const 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 string& desc);
    void withdraw(const Date& date, double amount, const string& desc);
    void settle(const Date& date);
    void show() const;
};



#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");
    else
        record(date, -amount, desc);
}
void SavingsAccount::settle(const Date& date) {
    double interest = accumulate(date) * rate / 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;
}


#include"account.h"
#include<iostream>
using namespace std;
int main() {
    Date date{ 2008,11,1 };
    SavingsAccount accounts[] = {
        SavingsAccount(date,"03755217",0.015),
        SavingsAccount(date,"02342342",0.015)
    };
    const int n = sizeof(accounts) / sizeof(SavingsAccount);
    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;
}