【LeetCode第 177 场周赛】5169. 日期之间隔几天

int isleap(int y){
    return y%4==0 && y%100!=0 || y%400==0;
}
int tab[]={-1,31,28,31,30,31,30,31,31,30,31,30,31};
int getdate1(char *date){ 
    int y,m,d,r=0;
    sscanf(date, "%d-%d-%d", &y,&m,&d);
    for(int i=1970; i<y;i++)
        if(isleap(i)) r+= 366;
        else r+= 365;
    for(int i=1;i<m;i++){
        r+=tab[i];
        if(i==2 && isleap(y)) r+=1;
    }
    r+=d;
    return r;
}
#define intfabs(x) ((x)<0?-(x):(x))
int daysBetweenDates(char * date1, char * date2){
    return intfabs(getdate1(date1)-getdate1(date2) );
}

作者：ni-jin-tian-zhen-hao-kan-2
链接：https://leetcode-cn.com/problems/number-of-days-between-two-dates/solution/fen-bie-ji-suan-liang-ri-qi-xiang-dui-yu-1970nian-/
来源：力扣（LeetCode）
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

class Solution {
public:
    int day_diff(int year_start, int month_start, int day_start
			, int year_end, int month_end, int day_end)
{
	int y2, m2, d2;
	int y1, m1, d1;
	
	m1 = (month_start + 9) % 12;
	y1 = year_start - m1/10;
	d1 = 365*y1 + y1/4 - y1/100 + y1/400 + (m1*306 + 5)/10 + (day_start - 1);
 
	m2 = (month_end + 9) % 12;
	y2 = year_end - m2/10;
	d2 = 365*y2 + y2/4 - y2/100 + y2/400 + (m2*306 + 5)/10 + (day_end - 1);
	
	return (d2 - d1);
}

    int daysBetweenDates(string date1, string date2) {
        int y1,y2,m1,m2,d1,d2;
        y1=stoi(date1.substr(0,4));
        y2=stoi(date2.substr(0,4));
        m1=stoi(date1.substr(5,2));
        m2=stoi(date2.substr(5,2));
        d1=stoi(date1.substr(8,2));
        d2=stoi(date2.substr(8,2));
        return abs(day_diff(y1,m1,d1,y2,m2,d2));
    }   
};