题解 | #获得月份天数#

#include<stdio.h>
int main() {
    int year, month;
    while (scanf("%d %d", &year, &month) != EOF) 
    {
        if (month == 4 || month == 6 || month == 9 || month == 11) 
        {
            printf("30\n");
        } else {
            switch (month) 
            {
                case 2:
                    if ((year % 4 == 0 && year % 100 != 0) || ( year % 400 == 0)) 
                    {
                        printf("29\n");
                    } else {
                        printf("28\n");
                    } break;
                default : printf("31\n");break;
            }
        }
    }
    return 0;
}