#include<iostream>
using namespace std;

//前置聲明
class Date;

//友元函數(shù)聲明
long operator-(Date c1,Date c2);
bool operator>(Date c1,Date c2);
bool operator<(Date c1,Date c2);
bool operator==(Date c1,Date c2);
istream & operator>>(istream &is,Date &c);
ostream & operator<<(ostream &out,const Date &c);

//定義錯(cuò)誤類
class wrongdate{};


//定義Date類
class Date
{
public:
	Date(int y=2000,int m=1,int d=1);
	void setdate(int y=2000,int m=1,int d=1);
	bool judgeyear();
	bool judgemonth();
	int month_day();
	bool judgeday();
	void judgedate();
	friend long operator-(Date c1,Date c2);
	Date operator+(int c2);
	Date operator-(int c2);
	Date operator++();
	Date operator--();
	Date operator++(int nouse);
	Date operator--(int nouse);
	Date operator+=(int c2);
	friend bool operator>(Date c1,Date c2);
	friend bool operator<(Date c1,Date c2);
	friend bool operator==(Date c1,Date c2);
	friend istream & operator>>(istream &is,Date &c);
	friend ostream & operator<<(ostream &out,const Date &c);
	void showdate();
private:
	int year,month,day,m;
};

//定義構(gòu)造函數(shù)
Date::Date(int y,int m,int d)
{
	year=y;
	month=m;
	day=d;
}

//定義賦值函數(shù)
void Date::setdate(int y,int m,int d)
{
	year=y;
	month=m;
	day=d;
}

//判斷年是否為閏年
bool leap_year(int year)
{
	return(year%4==0&&year%100!=0||year%400==0);
}

//定義類函數(shù)判斷年的合法性
bool Date::judgeyear()
{
	return(year!=0);
}

//定義類函數(shù)判斷月的合法性
bool Date::judgemonth()
{
	return(month>=1&&month<=12);
}

//定義類函數(shù)計(jì)算每個(gè)月返回的天數(shù)
int Date::month_day()
{
	switch(month)
	{
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:m=31;break;
	case 4:
	case 6:
	case 9:
	case 11:m=30;break;
	case 2:
		{
			if(leap_year(year))
			   m=29;
		    else 
				m=28;
		    break;
		}
	}
	return m;
}

//類函數(shù)判斷日的合法性
bool Date::judgeday()
{
	return(day>0&&day<=month_day());
}

//類函數(shù)判斷日期的合法性
void Date::judgedate()
{
	if((judgeyear()&&judgemonth()&&judgeday()));
	else
		throw wrongdate();	
}

//重載友元函數(shù)計(jì)算兩個(gè)日期相差的天數(shù)
long operator-(Date c1,Date c2)
{
	long dif1,dif2,dif=0;
	for(;c1.month>1;c1.month--)
		dif1=c1.day-1+c1.month_day();
	for(;c2.month>1;c2.month--)
		dif2=c2.day-1+c2.month_day();
	while(c1.year!=c2.year)
	{
		if(c1.year>c2.year)
		{
			if(leap_year(c2.year))
				dif+=366;
			else dif+=365;
			c2.year++;
		}
		if(c1.year<c2.year)
		{
			if(leap_year(c1.year))
				dif+=366;
			else dif+=365;
			c1.year++;
		}
	}
	return(c1.year>c2.year ? (dif+dif1-dif2):(dif+dif2-dif1));
}


//重載日期+天數(shù)
Date Date::operator+(int c2)
{
	while(c2!=0)
	{
		if(month>12)
		{
			month-=12;
			year++;
		}
		day++;
		c2--;
		if(day>month_day())
		{
			day-=month_day();
			month++;
		}
	}
	return(*this);
}

//重載日期-天數(shù)
Date Date::operator-(int c2)
{
	while(c2!=0)
	{
		if(month<1)
		{
			month=12;
			year--;
		}
		day--;
		c2--;
		if(day<1)
		{
			month--;
			day=month_day();
		}
	}
	return(*this);
}

//類函數(shù)重載前置++號(hào)
Date Date::operator++()
{
	*this=*this+1;
	return(*this);
}

//類函數(shù)重載前置--號(hào)
Date Date::operator--()
{
	*this=*this-1;
	return(*this);
}

//類函數(shù)重載后置++號(hào)
Date Date::operator++(int nouse)
{
	Date c1;
	c1=*this;
	*this=*this+1;
	return(c1);
}

//類函數(shù)重載后置--號(hào)
Date Date::operator--(int nouse)
{
	Date c1;
	c1=*this;
	*this=*this-1;
	return(c1);
}

//類函數(shù)重載+=號(hào)
Date Date::operator +=(int c2)
{
	*this=*this+c2;
	return(*this);
}

//友元函數(shù)重載〉判斷第一個(gè)日期比第二個(gè)日期后
bool operator>(Date c1,Date c2)
{
	long dif1,dif2;
	for(;c1.month>1;c1.month--)
		dif1=c1.day-1+c1.m;
	for(;c2.month>1;c2.month--)
		dif2=c2.day-1+c2.m;
	if(c1.year>c2.year)
		return true;
	if(c1.year==c2.year)
	{
		if(dif1>dif2)
			return true;
		else return false;
	}
	else return false;
}

//友元函數(shù)重載〈判斷第一個(gè)日期比第二個(gè)日期前
bool operator<(Date c1,Date c2)
{
	long dif1,dif2;
	for(;c1.month>1;c1.month--)
		dif1=c1.day-1+c1.m;
	for(;c2.month>1;c2.month--)
		dif2=c2.day-1+c2.m;
	if(c1.year<c2.year)
		return true;
	if(c1.year==c2.year)
	{
		if(dif1<dif2)
			return true;
		else return false;
	}
	else return false;
}

//友元函數(shù)重載==判斷兩個(gè)日期相等
bool operator==(Date c1,Date c2)
{
	long dif1,dif2;
	for(;c1.month>1;c1.month--)
		dif1=c1.day-1+c1.m;
	for(;c2.month>1;c2.month--)
		dif2=c2.day-1+c2.m;
	if(c1.year==c2.year&&dif1==dif2)
		return true;
	else return false;
}

//重載>>輸入函數(shù)
istream & operator>>(istream &is,Date &c)
{
	is>>c.year>>c.month>>c.day;
	return is;
}

//重載<<輸出函數(shù)
ostream & operator<<(ostream &out,const Date &c)
{
	out<<c.year<<"年"<<c.month<<"月"<<c.day<<"日"<<endl;
	return out;
}

//輸出年月日
void Date::showdate()
{
	cout<<year<<"年"<<month<<"月"<<day<<"日"<<endl;
}

//主函數(shù)
int main()
{
	Date c1,c2,c3;
	int i,j,k,l,m=0,n;
	long num,dif;
	int year,month,day;
	char a[10];

	//用字符串來輸入第一個(gè)日期，并判斷第一個(gè)日期的格式
	cout<<"輸入第一個(gè)日期_年_月_日"<<endl;
	cin>>a;
	//計(jì)算出年與月之間的字符所在的位數(shù)
	for(i=0;i<10;i++)
	{
		if(a[i]<'0'||a[i]>'9')
		{
			if(m==1) 
			{
				l=i;//用l記錄第二個(gè)非數(shù)字字符的位置
				m+=1;
			}
			if(m==0)
			{
				k=i;
			    m+=1;//用k記錄第一個(gè)非數(shù)字字符的位置
			}
		}
		if(a[i]=='\n'&&m==2)
		{
			n=i;
			break;//用n記錄結(jié)束字符的位置
		}
	}
	if(a[k]!=a[l])
	{
		cout<<"type wrong"<<endl;
        return(0);
	}

	//計(jì)算輸入的年
	year=(int)(a[0])-48;
	month=(int)(a[k+1])-48;
	day=(int)(a[l+1])-48;
	for(j=1;j<k;j++)
	   year=10*year+(int)(a[j])-48;
	for(j=k+2;j<l;j++)
	   month=10*month+(int)(a[j])-48;
    for(j=l+2;j<n;j++)
		day=10*day+(int)(a[j])-48;

	//輸入轉(zhuǎn)換后的第一個(gè)日期
	c1.setdate(year,month,day);
	c1.judgedate();

	//用重載的>>來輸入第二個(gè)日期
	cout<<"輸入第二個(gè)日期_年_月_日"<<endl;
	cin>>c2;
	c2.judgedate();

	//用拋出錯(cuò)誤類來判斷日期的合法性
	char ch='y';
	while()
	{
	if(ch=='y')
	try
	{
		c1.judgedate();
		c2.judgedate();
	}
	catch(wrongdate)
	{
		cout<<"輸入的日期錯(cuò)誤;是否繼續(xù)（y/n)"<<endl;
			cin>>ch;
	}
	else break;
	}
	if(ch!='y')
		exit(1);
	
	cout<<"輸入要加減的天數(shù)"<<endl;
	cin>>num;

	//測(cè)試兩個(gè)日期相差的天數(shù)
	dif=c1-c2;
	cout<<"兩個(gè)日期相差的天數(shù)"<<dif<<endl;

	//測(cè)試重載的+號(hào)
	c3=c1+num;
	cout<<"日期加天數(shù)的結(jié)果是";
	c3.showdate();

	//測(cè)試重載的-號(hào)
	c1.setdate(year,month,day);
	c3=c1-num;
	cout<<"日期減天數(shù)的結(jié)果是";
    cout<<c3;
	
	//測(cè)試重載的+=號(hào)
	c1.setdate(year,month,day);
	c1+=num;
	cout<<"c1+="<<num<<"="<<c1<<endl;

	//測(cè)試重載的后置++
	c1.setdate(year,month,day);
	cout<<"c1++="<<c1++<<endl;

	//測(cè)試重載的前置++
	c1.setdate(year,month,day);
	cout<<"++c1="<<++c1<<endl;

	//測(cè)試重載的后置--
	c1.setdate(year,month,day);
	cout<<"c1--="<<c1--<<endl;

	//測(cè)試重載的前置--
	c1.setdate(year,month,day);
	cout<<"--c1="<<--c1<<endl;

	//判斷兩個(gè)日期的大小
	if(c1>c2)
		cout<<"c1>c2"<<endl;
	if(c1<c2)
		cout<<"c1<c2"<<endl;
	if(c1==c2)
		cout<<"c1=c2"<<endl;
	return(0);
}