1:sum+=day;

2:if()

? {

? }要加括號

以下是修改過的程序，錯誤原因我給你注釋標注了，望采納-_-.//

#include?<stdio.h>
int?main()?
{?
????int?year?=?2008;
????int?month?=?8;
????int?day?=?8;
????int?sum?=0;
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;
}
????sum?+=?day;//逗號改為英文格式?,而且邏輯有錯誤?---總天數?應該是sum+day?
????if((year%4==0&&year%100!=0)||year%400==0)//if語句沒有加大括號?
???{
	?	sum+=1;?
????	printf("%d年%d月%d日是該年的第%d天",year,month,day,sum);
	}
????else
????printf("%d年%d月%d日是該年的第%d天",year,month,day,sum);
?
????return?0;
}