C语言月份的天数

C语言从键盘上输入年份和月份,计算并输出这一年的这一月共有多少天。

#include<stdio.h>
 
void main()
 
{
 
 int y, n, s = 0;//定义变量
 
 scanf_s("%d-%d", &y, &n);//输入年月
 
 switch (n)//根据月份判断天数
 
 {
 
 case 1:s = 31; break;
 
 case 2:s = 28; break;
 
 case 3:s = 31; break;
 
 case 4:s = 30; break;
 
 case 5:s = 31; break;
 
 case 6:s = 30; break;
 
 case 7:s = 31; break;
 
 case 8:s = 31; break;
 
 case 9:s = 30; break;
 
 case 10:s = 31; break;
 
 case 11:s = 30; break;
 
 case 12:s = 31; break;
 
 }
 
 if (n == 2)//判断闰年2月差异
 
 {
 
 if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0)
 
 s = 29;
 
 else
 
 s = 28;
 
 }
 
 printf("%d\n", s);
 
}