解释下列代码#include <iostream> #include <string> using namespace std; class Date { public: Date(int year, int month, int day) : year_(year), month_(month), day_(day) {}; friend ostream& operator<<(ostream& os, const Date& date) { os << date.year_ << "-" << date.month_ << "-" << date.day_; return os; } private: int year_; int month_; int day_; }; class Person { public: Person(const string& name, const Date& birthday) : name_(name), birthday_(birthday) {}; virtual ~Person() {}; protected: string name_; Date birthday_; }; class Teacher : public Person { public: Teacher(const string& id, const string& name, const Date& birthday, const string& major, const string& affiliation) : Person(name, birthday), id_(id), major_(major), affiliation_(affiliation) {}; void PrintInfo() const { cout << "Name: " << name_ << endl; cout << "Birthday: " << birthday_ << endl; cout << "Teacher ID: " << id_ << endl; cout << "Teaching Major: " << major_ << endl; cout << "Affiliation: " << affiliation_ << endl; cout << "The basic information: " << id_ << ' ' << name_ << ' ' << birthday_ << ' ' << major_ << ' ' << affiliation_ << endl; } private: string id_; string major_; string affiliation_; }; class Student : public Person { public: Student(const string& id, const string& name, int score, const Date& birthday) : Person(name, birthday), id_(id), score_(score) {}; void PrintInfo() const { cout << "Name: " << name_ << endl; cout << "Birthday: " << birthday_ << endl; cout << "Student ID: " << id_ << endl; cout << "Student Score: " << score_ << endl; cout << "The basic information: " << id_ << ' ' << name_ << ' ' << score_ << endl; cout << birthday_ << endl; } private: string id_; int score_; }; int main() { Date student_birthday(1976, 5, 27); //修改学生出生日期 Student student("2023007", "kxiong", 92, student_birthday); student.PrintInfo(); Date teacher_birthday(1998, 1, 7); //修改教师出生日期 Teacher teacher("20210058", "xsong", teacher_birthday, "Computer Science", "CTBu"); teacher.PrintInfo(); return 0; }

这段代码定义了四个类：Date、Person、Teacher和Student。其中，Date类表示日期，Person类表示人，Teacher和Student是Person的两个派生类，表示教师和学生。每个类都有一些成员变量和成员函数。

在主函数中，首先创建了一个学生对象，然后修改了学生的出生日期，并调用PrintInfo函数打印学生的信息。接着，创建了一个教师对象，修改了教师的出生日期，并调用PrintInfo函数打印教师的信息。

在Person类中，定义了一个纯虚析构函数，表示Person类是一个抽象类，不能直接创建Person对象，只能创建派生类的对象。在Teacher和Student类中，分别定义了PrintInfo函数，用于打印教师和学生的信息。在Date类中，重载了<<运算符，用于打印日期信息。

相关问题

#include <iostream> using namespace std; class Date { public: int year,month,day; Date(int year=2000,int month=1,int day=1):year(year),month(month),day(day) {} }; class Cperson { private: string Name; string Num; Date brith; Cperson(const char *pName="张三", string Num="123456789123456789", int year=2000,int month=1,int day=1): Name(Name),Num(Num),brith(year,month,day) {} string GetName() { return Name; } string GetNum() { return Num; } int Getbrith() { return brith; } }; cass Cstudent: private Cperson { private: int StNum; }; class Cteacher:public Cperson { private: Date Time; }; int main() { cout << "手机编程APP"; return 0; }有什么错误

在类Cperson的构造函数中，初始化成员变量时，应该使用初始化列表中的参数，而不是使用类内部定义的变量。正确的构造函数应该是：

Cperson(const char *pName="张三",
        string Num="123456789123456789",
        int year=2000,int month=1,int day=1):
    Name(pName),Num(Num),brith(year,month,day)
{}

此外，在类Cperson的成员函数Getbrith中，返回值应该是一个Date对象，而不是int类型。应该改为：

Date Getbrith()
{
    return brith;
}

最后，在类Cstudent和Cteacher中，应该声明访问权限为public，否则外部无法访问这些类的成员。修正后的代码如下：

#include <iostream>
using namespace std;

class Date {
public:
    int year,month,day;
    Date(int year=2000,int month=1,int day=1):year(year),month(month),day(day)
    {}
};

class Cperson {
public:
    string Name;
    string Num;
    Date brith;
    Cperson(const char *pName="张三",
            string Num="123456789123456789",
            int year=2000,int month=1,int day=1):
        Name(pName),Num(Num),brith(year,month,day)
    {}
    string GetName()
    {
        return Name;
    }
    string GetNum()
    {
        return Num;
    }
    Date Getbrith()
    {
        return brith;
    }
};

class Cstudent: public Cperson {
public:
    int StNum;
};

class Cteacher:public Cperson {
private:
    Date Time;
public:
    // 省略构造函数
};

int main() {
    cout << "手机编程APP";
    return 0;
}

设计符合下述要求的日期类（Date），使得下述代码可以正常运行。 拥有数据成员year、month和day，分别存储年、月、日； 构造函数接受年、月、日参数并初始化全部数据成员； 公有成员函数toText()返回一个string对象，该字符串为该日期对象的文字表达，比如“2022-5-20”； 公有成员函数nextDay()返回一个Date对象，表示该日期的后一天； 公有成员函数prevDay()返回一个Date对象，表示该日期的前一天。 裁判测试程序样例： #include <iostream> #include <string> #include <assert.h> using namespace std; //请在此处定义Date类 int main() { int year=2000,month=1,day=1; cin >> year >> month >> day; Date d(year,month,day); cout << "Date: " << d.toText() << ", Next Day: " << d.nextDay().toText() << ", Prev Day: " << d.prevDay().toText(); return 0; } 输入样例： 2000 3 1 说明：依次是年-月-日。 输出样例： Date: 2000-3-1, Next Day: 2000-3-2, Prev Day: 2000-2-29 提示：需要注意闰年，闰年2月有29天，平年28天。 闰年判定函数： bool isLeapYear(int year){ //四年一闰，百年不闰，四百年又闰 if (year%400==0) return true; else if (year%100==0) return false; else if (year%4==0) return true; else return false; }

#include <iostream>
#include <string>
#include <assert.h>
using namespace std;

class Date {
private:
    int year, month, day;
public:
    Date(int y, int m, int d) {
        year = y;
        month = m;
        day = d;
    }
    string toText() {
        string s = to_string(year) + "-";
        if (month < 10)
            s += "0";
        s += to_string(month) + "-";
        if (day < 10)
            s += "0";
        s += to_string(day);
        return s;
    }
    bool isLeapYear(int year) {
        if (year % 400 == 0)
            return true;
        else if (year % 100 == 0)
            return false;
        else  if (year % 4 == 0)
            return true;
        else
            return false;
    }
    Date nextDay() {
        int daysInMonth;
        if (month == 2) {
            if (isLeapYear(year))
                daysInMonth = 29;
            else
                daysInMonth = 28;
        }
        else if (month == 4 || month == 6 || month == 9 || month == 11) {
            daysInMonth = 30;
        }
        else {
            daysInMonth = 31;
        }
        if (day == daysInMonth) {
            if (month == 12) {
                year++;
                month = 1;
                day = 1;
            }
            else {
                month++;
                day = 1;
            }
        }
        else {
            day++;
        }
        return Date(year, month, day);
    }
    Date prevDay() {
        if (day == 1) {
            if (month == 1) {
                year--;
                month = 12;
                day = 31;
            }
            else {
                month--;
                if (month == 2) {
                    if (isLeapYear(year))
                        day = 29;
                    else
                        day = 28;
                }
                else if (month == 4 || month == 6 || month == 9 || month == 11) {
                    day = 30;
                }
                else {
                    day = 31;
                }
            }
        }
        else {
            day--;
        }
        return Date(year, month, day);
    }
};

int main() {
    int year = 2000, month = 1, day = 1;
    cin >> year >> month >> day;
    Date d(year, month, day);
    cout << "Date: " << d.toText() << ", Next Day: " << d.nextDay().toText() << ", Prev Day: " << d.prevDay().toText();
    return 0;
}