类实现明天的日期

#include <iostream>
#include <algorithm>
using namespace std;
class TDate 
{
    public:
        TDate(int y,int m,int d):year(y),month(m),day(d)
        {}
        TDate(){}
        void print()
        {
            cout<<year<<"/"<<month<<"/"<<day<<endl;
        }
        TDate tomorrow(TDate date1)
        {
            int day[20]={0,31,28,31,30,31,30,31,31,30,31,30,31};
            int yy=date1.year;
            int mm=date1.month;
            int dd=date1.day;
            if(yy%400==0||(yy%4==0&&yy%100!=0))    day[2]++;
            if(mm==12&&dd==31)    {    yy++,mm=1,dd=1;    }
            else if(dd+1>day[mm])    {    dd=1,mm++;    }
            else {    dd++;    }
            TDate date3(yy,mm,dd);
            return date3;
        }
    private:
        int year,month,day;
};
int main()
{
    TDate d1(2003,12,31);
    d1.print();
    TDate d2=d1.tomorrow(d1);
    d2.print();
    return 0;
}