这样写的结果为什么不对
#include <stdio.h>
int main()
{
/* 定义需要计算的日期 */
int year = 2008;
int month = 8;
int day = 8;
int sum,f;
switch(month)
{
case 1:sum=0;
break;
case 2:sum+=31;
break;
case 3:sum+=28;
break;
case 4:sum+=31;
break;
case 5:sum+=30;
break;
case 6:sum+=31;
break;
case 7:sum+=30;
break;
case 8:sum+=31;
break;
case 9:sum+=31;
break;
case 10:sum+=30;
break;
case 11:sum+=31;
break;
case 12:sum+=30;
break;
case 13:sum+=31;
break;
}
sum+=day;
if(year%4==0)
{
f=1;}
else
{f=0;}
if(f==1&&month>2)
sum++;
printf("2008年8月8日是该年的第%d天\n",sum);
return 0;
}