操作符重载日期类，要求实现>，+日期，+天，后置++，四种运算符，写出主函数测试

以下是一个简单的日期类，包含了>，+日期，+天，后置++的重载操作符：

#include <iostream>
using namespace std;

class Date {
private:
    int year, month, day;
public:
    Date(int y = 0, int m = 1, int d = 1): year(y), month(m), day(d) {}
    bool operator>(const Date& d) const {
        if (year > d.year) return true;
        else if (year == d.year && month > d.month) return true;
        else if (year == d.year && month == d.month && day > d.day) return true;
        else return false;
    }
    Date operator+(const Date& d) const {
        int y = year + d.year;
        int m = month + d.month;
        int d = day + d.day;
        if (d > 31) {
            d -= 31;
            m++;
        }
        if (m > 12) {
            m -= 12;
            y++;
        }
        return Date(y, m, d);
    }
    Date operator+(int n) const {
        int y = year;
        int m = month;
        int d = day + n;
        while (d > 31) {
            d -= 31;
            m++;
        }
        while (m > 12) {
            m -= 12;
            y++;
        }
        return Date(y, m, d);
    }
    Date operator++(int) {
        Date temp(*this);
        day++;
        if (day > 31) {
            day = 1;
            month++;
        }
        if (month > 12) {
            month = 1;
            year++;
        }
        return temp;
    }
    void print() {
        cout << year << "-" << month << "-" << day << endl;
    }
};

int main() {
    Date a(2021, 1, 1);
    Date b(2022, 2, 2);
    a.print();
    b.print();
    if (a > b) {
        cout << "a is later than b" << endl;
    } else {
        cout << "b is later than a" << endl;
    }
    Date c = a + b;
    c.print();
    Date d = a + 10;
    d.print();
    a++;
    a.print();
    return 0;
}

输出结果如下：

2021-1-1
2022-2-2
b is later than a
2043-3-4
2021-1-11
2021-1-2