d017: 打印某年某月有几天

 1 #include <stdio.h>
 2 int main(void)
 3 {
 4     int y, m;
 5     scanf("%d %d", &y, &m);
 6     switch (m)
 7     {
 8         case 1:
 9         case 3:
10         case 5:
11         case 7:
12         case 8:
13         case 10:
14         case 12:
15             printf("31");
16             break;
17         case 4:
18         case 6:
19         case 9:
20         case 11:
21             printf("30");
22             break;
23         case 2:
24             if ((y%400 == 0) || (y%4 == 0) && (y%100 != 0))
25                 printf("29");
26             else
27                 printf("28");
28     }
29     return 0;
30 }