//file:date.h
#include<iostream.h>
class date
{
public:
    date(){year=month=day=leapyear=pastdays=week=-1;};
    date(int y,int m,int d);
    int getweek(){return week;};
    friend bool operator<(date& dt1,date& dt2);
    friend long leapyearsbetween(date dt1,date dt2);
    friend ostream& operator<<(ostream& out,date& dt);
    friend long operator-(date dt1,date dt2);
    date& operator+=(int days);
protected:
    int year,month,day;
    int leapyear,pastdays,week;
};

//file:date.cpp
#include<iomanip.h>
#include "date.h"
date::date(int y,int m,int d)
{
    static int
        r1[13]={0,31,28,31,30,31,30,31,31,30,31,30,31},
        r2[13]={0,0,3,3,6,1,4,6,2,5,0,3,5},
        r3[13]={0,0,31,59,90,120,151,181,212,243,273,304,334};
    int c;
    if(y<0||m<1||m>12||d<1)
    {
        cerr<<"Wrong Date!"<<endl;
        year=month=day=leapyear=pastdays=week=-1;
        return;
    }
    if(y%4==0&&y%100!=0||y%400==0)leapyear=1;
    else leapyear=0;
    if(d>r1[m]+(m==2?leapyear:0))
    {
        cerr<<"Wrong Date!"<<endl;
        year=month=day=leapyear=pastdays=week=-1;
        return;
    }
    year=y;month=m;day=d;//日期数据约束条件
    y%=400;
    if(leapyear&&m<3)c=5;
    else c=6;
    week=(y+y/4-y/100+r2[m]+d+c)%7;
    pastdays=r3[m]+d;
    if(leapyear&&m>2)++pastdays;
}
ostream& operator<<(ostream& out,date& dt)
{
    out<<setw(4)<<dt.year<<"/"
        <<setw(2)<<setfill('0')<<dt.month<<"/"
        <<setw(2)<<setfill('0')<<dt.day;
    return out;
}
bool operator<(date& dt1,date& dt2)
{
    if(dt1.year<dt2.year)return true;
    if(dt1.year>dt2.year)return false;
    if(dt1.month<dt2.month)return true;
    if(dt1.month>dt2.month)return false;
    if(dt1.day<dt2.day)return true;
    return false;
}
long leapyearsbetween(date dt1,date dt2)//dt1<dt2
{
    long y1=dt1.year,y2=dt2.year-1;
    long lys;
    for(;!(y1%4==0&&y1%100!=0||y1%400==0);++y1);
    if(y1>y2)return 0;
    for(lys=0;y1<=y2;y1+=4)
        if(y1%100!=0||y1%400==0)++lys;
    return lys;
}
long operator-(date dt1,date dt2)
{
    long sign=1;
    if(dt1<dt2)
    {date temp=dt1;dt1=dt2;dt2=temp;sign=-1;}
    long lys=leapyearsbetween(dt2,dt1);
    return sign*((dt1.year-dt2.year)*365+lys+dt1.pastdays-dt2.pastdays);
}
date& date::operator+=(int days)//后数天数
{
    static int r[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
    int t;
    if(days>=(t=366+leapyear-pastdays))
    {
        days-=t;
        ++year;month=day=1;
    }
    while(days>(t=365+leapyear))
    {
        days-=t;
        ++year;
    }
    while(days>=r[month]+(month==2&&leapyear?1:0))
    {
        days-=r[month]+(month==2&&leapyear?1:0);
        ++month;
    }
    day+=days;
    if(day>r[month]+(month==2&&leapyear?1:0)){day-=r[month]+(month==2&&leapyear?1:0);++month;}
    if(month>12){month=1;++year;}
    return *this;
}

//file:test.cpp
#include "date.h"
void main()
{
    int y,m,d;
    date d1,d2;
    cout<<"输入第一个日期：年月日"<<endl;
    cin>>y>>m>>d;
    d1=date(y,m,d);
    while(1)
    {
    cout<<"输入后数天数："<<endl;
    cin>>d;if(d==-1)break;
    d1+=d;
    cout<<"到"<<d1<<endl;
    }
}

评论