#include<iostream.h>
class Date
{
int yr,mo,day;
static const int dys[];
bool Leapyear(int y)const
{ return (y%4==0&&y%100!=0)||(y%400==0); }
public:
Date(){yr=mo=day=1;}
Date(int y,int m,int d)
{ yr=y;mo=m;day=d; }
Date(const Date& dt)
{ yr=dt.yr;
mo=dt.mo;
day=dt.day;
}
Date(long ndays)
{
if(ndays==0)
yr=mo=day=0;
else
{
day=ndays;
yr=1;
while(1)
{
int n=Leapyear(yr)?366:365;
if(day<=n) break;
day-=n;
++yr;
}
for(mo=1;mo<13;mo++)
{
int n=dys[mo-1];
if(mo==2&&Leapyear(yr))
n++;
if(day<=n) break;
day-=n;
}
}
}
~Date(){}
Date &operator=(const Date& dt)
{
yr=dt.yr;mo=dt.mo;day=dt.day;
return *this;
}
operator long()const
{
long ndays=0;
for(int i=1;i<yr;++i)
ndays+=Leapyear(i)?366:365;
for(int i=1;i<mo;++i)
ndays+=dys[i-1];
if(mo>2&&Leapyear(yr))
++ndays;
ndays+=day;
return ndays;
}
Date operator--(int)
{
Date temp(*this);
long ndays=*this;
--ndays;
*this=ndays;
return *this;
}
void Display()const
{
cout<<yr<<'/'<<mo<<'/'<<day<<endl;
}
};
const int Date::dys[]={31,28,31,30,31,30,31,31,30,31,30,31};
int main()
{
Date d;
d.Display();
Date d1(2012,2,10);
d1.Display();
d=d1--;
d.Display();
d1.Display();
return 0;
}
