编译器为vc2010
#include<stdio.h>
#include<Windows.h>
int main(void){
int year,mouth,day,sum=0,i;
int a[12]={0,31,28,31,30,31,30,31,31,30,31,30};
printf("请输入年月日:");
scanf("%d%d%d",&year,&mouth,&day);
for(i=mouth-1;i>=0;i--){
sum=sum+a[i];
}
sum=sum+day;
if((year%4==0&&year%100!=0)||year%400==0){
sum=sum+1;
}
printf("输入日期是这一年第%d天\n",sum);
system("pause");
return 0;
}