题解 | #获得月份天数#

#include <stdio.h>

int main() {
    int a, b;

    //31 天 1 3 5 7 8 10 12
    //30 天 4 6 9 11
    //润
    while (   scanf("%d %d", &a, &b) != EOF) 
	{
        if (((a % 4 == 0 && a % 100 != 0) || (a % 400 == 0) && (b == 2))) {
            printf("%d\n", 29);
        } else if (b == 2) {
            printf("%d\n", 28);
        } else if (b == 4 || b == 6 || b == 9 || b == 11) {
            printf("%d\n", 30);
        } else {
            printf("%d\n", 31);
        }
    }

    return 0;
}