15.c

这是一个经过本人一个月的时间自己做的关于c的小程序

#include<stdio.h>
void year_day()//判断年月的天数
{
	int y,d;
	scanf("%d,%d",&y,&d);
	switch(d)
	{
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:
		printf("this month is 31 days!\n");
		break;
	case 4:
	case 6:
	case 9:
	case 11:
		printf("this month is 30 days!\n");
		break;
	case 2:
		if(y%4==0||y%400==0)
	
			printf("this month is 29 days!\n");
		else

			printf("this month is 28 days!\n");	
		break;
	default:
		break;

	}
}