第十七周项目四 日期结构体-（2）两人生日差几天

#include <iostream>
using namespace std;
struct Date
{
    int year;
    int month;
    int day;
};
int days(int,int,int);
int main()
{
    Date date1,date2;
    cout<<"input player1's birthday year,month,day:";
    cin>>date1.year>>date1.month>>date1.day;
    cout<<"input player2's birthday year,month,day:";
    cin>>date2.year>>date2.month>>date2.day;
    //计算days
    int days1= days(date1.year,date1.month,date1.day);
    int days2= days(date2.year,date2.month,date2.day);
    int d=days1-days2;
    if (d<0)
        d=-d;
    cout<<"Birthday is "<<d<<" days apart."<<endl;
    return 0;
}
int days(int date_year,int date_month,int date_day)
{
    int i,days_1980=0;
    int day[13]= {0,31,28,31,30,31,30,31,31,30,31,30,31};
    for ( i=1980; i<date_year; i++)
    {
        days_1980+=365;
        if ((i%4==0&&i%100!=0)||i%400==0)
            days_1980++;
    }
    if ((date_year%4==0&&date_year%100!=0)||date_year%400==0)
        day[2]=29;
    else day[2]=28;
    for (i=0; i<date_month; i++)
        days_1980+=day[i];
    days_1980+=date_day;
    return days_1980;
}