// 引用自
https://bbs.bccn.net/viewthread.php?tid=290041&pid=1686402&page=1#pid1686402
#include<stdio.h>
int main(void)
{
int year,month,day,sum,leap;
printf("\n please input year,month,day\n");
scanf("%d,%d,%d",&year,&month,&day);
switch(month){
case 1:sum=0;break;
case 2:sum=31;break;
case 3:sum=59;break;
case 4:sum=90;break;
case 5:sum=120;break;
case 6:sum=151;break;
case 7:sum=181;break;
case 8:sum=212;break;
case 9:sum=243;break;
case 10:sum=273;break;
case 11:sum=304;break;
case 12:sum=334;break;
default:printf("data error");break;
}
sum=sum+day;
if(year%400==0||year%4==0&&year%100!=0)
leap=1;
else leap=0;
if(leap==1&&month>2);
sum++;
printf("It is the %dth day.",sum);
return 0;
}