题解 | 打印日期

#include <iostream>
using namespace std;
#include <assert.h>
class Date
{
public:
    Date(int year = 0,int month = 0,int day = 0)
        :_year(year)
        ,_month(month)
        ,_day(day)
    {}
    inline int GetMonthDay(int year, int month)
    {
        assert(month > 0 && month < 13);
        static int monthDayArray[13] = { -1, 31, 28, 31, 30, 31, 30, 31, 31, 30,31, 30,  31 };

        // 365天 5h +
        if (month == 2 && ((year % 4 == 0 && year % 100 != 0) || (year % 400 ==0)))
        {
            return 29;
        }
        else
        {
            return monthDayArray[month];
        }
    }

    void Print()
    {
       // cout<<_year<<"-"<<_month<<"-"<<_day<<endl;
       //输出把我打败了
       printf("%04d-%02d-%02d\n",_year,_month,_day);
    }
    Date& operator+=(int day)
    {
        _day += day;
        // =不执行，比如下个月28，则就是x月28天
        while(_day>GetMonthDay(_year,_month))
        {
            _day -= GetMonthDay(_year, _month);
            ++_month;
            if(_month == 13)
            {
                _month = 1;
                ++_year;
            }
        }
        return *this;
    }

private:
    int _year;
    int _month;
    int _day;
};

int main() {
    int year = 0;
    int numbers_of_day = 0;
    while(scanf("%d%d",&year,&numbers_of_day)!=EOF)
    {
        Date d(year,1,0);
        d+=numbers_of_day;
        d.Print();
    }
    return 0;
}