题解 | #BC74 获得月份天数#

#include <stdio.h>
#include <stdbool.h>

#define LeapYear(y) (y%400 == 0) || ((y%4==0) && (y%100!=0))

int main() {
    int y, m, d;
    int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    while(scanf("%d%d", &y, &m) != EOF) {
        d = days[m-1];
        if ((LeapYear(y) == true) && (m == 2)) {
            d = 29;
        }
        printf("%d\n", d);
    }
    return 0;
}