C++ 實驗一 創建CDate類

代碼：

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>

using namespace std;

class CDate
{
private:
    int year, month, day;

public:
    CDate()
    {
        year = 2000;
        month = 1;
        day = 1;
    }
    CDate(int year1, int month1, int day1)
    {
        year = year1;
        month = month1;
        day = day1;
    }
    ~CDate()
    {
        cout << "析構了" << endl;
    }
    void print()
    {
        cout << year << "年" << month << "月" << day << "日" << endl;
    }
    bool LeapYear(int year2)
    {
        if ((year2 % 4 == 0 && year2 % 100 != 0) || year2 % 400 == 0)
            return true;
        else
            return false;
    }
    void AddOneDay()
    {
        if (++day > GetDays())
        {
            day = 1;
            if (++month > 12)
            {
                month = 1;
                year++;
            }
        }
    }
    void SubOneDay()
    {
        if (--day == 0)
        {
            if (--month == 0)
            {
                month = 12;
                year--;
            }
            day = GetDays();
        }
    }
    void AddDays(int i)
    {
        while (i >= 366)
        {
            if (LeapYear(year) && month <= 2)
            {
                if (month == 2 && day == 29)
                {
                    AddOneDay();
                }
                i -= 366;
                year++;
            }
            else if (LeapYear(year + 1) && month >= 3)
            {
                i -= 366;
                year++;
            }
            else
            {
                i -= 365;
                year++;
            }
        }
        for (int t = 0; t < i; t++)
        {
            AddOneDay();
        }
    }
    void SubDays(int i)
    {
        while (i >= 366)
        {
            if (LeapYear(year) && month >= 3)
            {
                i -= 366;
                year--;
            }
            else if (LeapYear(year - 1) && month <= 2)
            {
                i -= 366;
                year--;
            }
            else
            {
                i -= 365;
                year--;
            }
        }
        for (int t = 0; t < i; t++)
        {
            SubOneDay();
        }
    }
    int GetDays()
    {
        int days = 0;
        switch (month)
        {
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12:
            days = 31;
            break;
        case 4:
        case 6:
        case 9:
        case 11:
            days = 30;
            break;
        case 2:
            if (((year % 4 == 0) && (year % 100 != 0)) || ((year % 400) == 0))
                days = 29;
            else
                days = 28;
        }
        return days;
    }
};
int main()
{
    cout<<"請輸入當前的年月日:"<<endl;
    int year,month,day;
    cin>>year>>month>>day;
    CDate d1(year,month,day);
    //d1.AddOneDay();
    d1.print();
    cout<<"請輸入要增加的天數"<<endl;
    int add_days;
    cin>>add_days;
    d1.AddDays(add_days);
    d1.print();
    cout<<"請輸入要減少的天數"<<endl;
    int sub_days;
    cin>>sub_days;
    d1.SubDays(sub_days);
    d1.print();
    return 0;
}