题解 | #获得月份天数#

#include<iostream>
using namespace std;
int main() {
    int a, m, d;
    while (cin >> a >> m) {
        if ((0 == a % 4 && a % 100 != 0) || (0 == a % 400))
            switch (m) {
                case 1:
                case 5:
                case 3:
                case 7:
                case 8:
                case 10:
                case 12:
                    d = 31;
                    break;
                case 2:
                    d = 29;
                    break;
                default :
                    d = 30;
            } else
            switch (m) {
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12:
                    d = 31;
                    break;
                case 2:
                    d = 28;
                    break;
                default:
                    d = 30;
            }
        cout << d << endl;
    }
    return 0;
}