C语言 定义一个结构体变量(包括年、月、日)，计算该日在本年中是第几天

#include <stdio.h>
struct{
    
    
	int year;
	int month;
	int day;
}date;
int main(){
    
    
	int days;
	printf("input year,month,day：");
	scanf("%d,%d,%d",&date.year,&date.month,&date.day);
	switch(date.month){
    
    
		case 1:days=date.day; 	   break;
		case 2:days=date.day+31;   break;
		case 3:days=date.day+59;   break;
		case 4:days=date.day+90;   break;
		case 5:days=date.day+120;  break;
		case 6:days=date.day+151;  break;
		case 7:days=date.day+181;  break;
		case 8:days=date.day+212;  break;
		case 9:days=date.day+243;  break;
		case 10:days=date.day+273; break;
		case 11:days=date.day+304; break;
		case 12:days=date.day+334; break;
	}
	if((date.year%4==0&&date.year%100!=0||date.year%400==0)&&date.month>=3)
		days+=1;
	printf("%d/%d is the %dth day in %d.",date.month,date.day,days,date.year);
	return 0;
}