编辑代码

#include <stdio.h>
int main () {
    int n,y,r,sum;
	printf("输入年月日：");
	scanf("%d%d%d",&n,&y,&r);
	switch(y){
		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 +=r;
	if((n%4==0&&n%100!=0||n%400==0)&&y>=3){
		sum++;
	}
	printf("该日期为本年的第%d天",sum);
	return 0;
}