#include<stdio.h>
int main()
{
 int year=2008,month=8,day=8,date=day;
 switch(month)
 {
  case 12:
   date+=30;
   
  case 11:
   date+=31;
  
  case 10:
   date+=30;
  
  case 9:
   date+=31;

  case 8:
   date+=31;

  case 7:
   date+=30;

  case 6:
   date+=31;

  case 5:
   date+=30;

  case 4:
   date+=31;

  case 3: 
   if((year%4==0&&year%100!=0)||year%400==0)
   {
    date+=29;
   }else{
   date+=28;}
  
  case 2:
   date+=31;
  
  case 1:
   break;
 }
 printf("%d年%d月%d日是该年的第%d天\n",year,month,day,date);
 return 0;
}输出结果多一天；

#include<stdio.h>
int main()
{
 int year=2008,month=8,day=8,date=day;
 switch(month)
 {
  case 12:
   date+=30;
   break;
  case 11:
   date+=31;
   break;
  case 10:
   date+=30;
   break;
  case 9:
   date+=31;
   break;
  case 8:
   date+=31;
   break;
  case 7:
   date+=30;
   break;
  case 6:
   date+=31;
   break;
  case 5:
   date+=30;
   break;
  case 4:
   date+=31;
   break;
  case 3: 
   if((year%4==0&&year%100!=0)||year%400==0)
   {
    date+=29;
   }else{
   date+=28;}
   break;
  case 2:
   date+=31;
   break;
  case 1:
   break;
 }
 printf("%d年%d月%d日是该年的第%d天\n",year,month,day,date);
 return 0;
}卡在一月。