实现代码：
int getmonthday(int year, int month )
{
int montharr[] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
int day = montharr[month ];
if (month == 2 && leapyear(year))
{
day = day + 1;
}
return day;
}
bool leapyear( int year )
{
if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
{
return true ;
}
return false ;
}
#ifndef _CALENDAR__H _
#include<assert.h>
#include <iostream>
using namespace std;
class calendar
{
friend bool leapyear(int year);
friend int getmonthday(int year, int month);
public:
void SetDate(int year, int month , int day)
{
_year = year;
_month = month;
_day = day;
}
calendar( int year = 1990, int month = 1, int day = 1)
{
if (year >= 1990 && month <= 12 && month > 0 && day > 0 && day <= getmonthday(year, month))
{
_year = year;
_month = month;
_day = day;
}
else
{
cout << "输入错误" << endl;
_year = 1990;
_month = 1;
_day = 1;
}
}
calendar( calendar &d )
{
_year = d._year;
_month = d._month;
_day = d._day;
}
void display()
{
cout << _year << "-" << _month << "-" << _day << endl;
}
private:
int _year;
int _month;
int _day;
public:
bool operator==(const calendar& d)
{
return (_year == d ._year &&_month == d._month&&_day == d ._day);
}
bool operator!=(const calendar& d)
{
return !(*this == d);
}
bool operator>(const calendar& d)
{
return (_year > d ._year&&_month > d._month&&_day > d ._day);
}
bool operator>=(const calendar& d)
{
return (*this > d || * this == d );
}
bool operator<(const calendar& d)
{
return !(*this > d || * this == d );
}
bool operator<=(const calendar& d)
{
return !(*this > d);
}
calendar& operator--()
{
* this -= 1;
return *this ;
}
calendar operator--(int )
{
calendar temp(*this );
* this -= 1;
return temp;
}
calendar& operator++()
{
* this += 1;
return *this ;
}
calendar operator++(int )
{
calendar temp(*this );
* this += 1;
return temp;
}
calendar operator+(int day)
{
calendar temp(*this );
if (day <0)
{
return *this - (-day);
}
temp._day += day;
while (temp._day > getmonthday(temp._year, temp._month))
{
temp._day -= getmonthday(temp._year, temp._month);
if (temp._month == 12)
{
temp._year++;
temp._month = 1;
}
else
{
temp._month++;
}
}
return temp;
}
calendar operator-(int day)
{
calendar temp(*this );
if (day < 0)
{
return *this + (-day);
}
temp._day -= day;
while (temp._day<=0)
{
if (temp._month == 1)
{
temp._year--;
temp._month = 12;
}
else
{
temp._month--;
}
temp._day += getmonthday(_year, _month);
}
return temp;
}
calendar operator-=(int day)
{
* this = *this - day;
return *this ;
}
calendar operator+=(int day)
{
* this = *this + day;
return *this ;
}
int operator-( calendar &d)
{
int flag = 1;
calendar max = *this ;
calendar min = d ;
if (max < min)
{
std::swap(max._year, min._year);
std::swap(max._month, min._month);
std::swap(max._day, min._day);
flag = -1;
}
int count = 0;
while (max != min)
{
++count;
++min;
}
return (count*flag);
}
};
#endif// _CALENDAR__H _
