题解 | #获得月份天数#

#include <stdio.h>

int main() {
    int year = 0;
    int month = 0;
    while (scanf("%d %d", &year, &month) != EOF) {
        if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
            switch (month) {
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12:
                    printf("31\n");
                    break;
                case 4:
                case 6:
                case 9:
                case 11:
                    printf("30\n");
                    break;
                case 2:
                    printf("29\n");
                    break;
                default:
                    printf("输入错误，重新输入");
                    break;
            }
        } else {
            switch (month) {
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12:
                    printf("31\n");
                    break;
                case 4:
                case 6:
                case 9:
                case 11:
                    printf("30\n");
                    break;
                case 2:
                    printf("28\n");
                    break;
                default:
                    printf("输入错误，重新输入");
                    break;
            }
        }
    }
    return 0;
}