2021年某月有几天（c++）

Question

Answer 1

#include<iostream>
using namespace std;
int main() {
    int n,d;
    cin >> n;
    switch(n) {
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12:
            d = 31;
            break;
        case 4:
        case 6:
        case 9:
        case 11:
            d = 30;
            break;
        case 2:
            d = 28;
            break;
        default:
            cout << "月份输入错误！";
            return 0;
    }
    cout << d;
    return 0;
}