#include?<stdio.h>
int?main()?
{?
????/*?定義需要計算的日期?*/
????int?year?=?2008;//需計算的年份
????int?month?=?8;//需計算的月份
????int?day?=?8;//需計算的日
????//定義總天數和判斷是否是閏年的狀態位
????int?sum,?flag;
????//使用switch語句計算月數的天數
????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("一年中只有十二個月！")；break;
????}
????
????//計算天數
????sum?=?sum?+?day;
????//當該年為閏年的時候，將狀態設置為1否則設置為0
????if(year%400?==?0||(year%4?==?0?&&?year%100?!=?0))
????????flag?=?1;
????else
????????flag?=?0;
????????//當需要計算的日期是閏年并且需計算的月份大于2月時，計算的天數自動加1
????????if(flag?==?1?&&?month?>?2)
????????sum++;
????????printf("%d年%d月%d日是該年的第%d天",year,month,day,sum);
????return?0;
}