题解 | #今年的第几天？#

#include <iostream>
#include <vector>
using namespace std;
struct Date {
    int year;
    int month;
    int day;
};
int countDay(Date date) {
    int sum = 0;
    vector<int> pn{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    vector<int> rn{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    if ((date.year % 400 == 0) || (date.year % 4 == 0 && date.year % 100 != 0)) {
        for (int i = 0; i < date.month - 1; i++) {
            sum += rn[i];
        }
        sum += date.day;
    } else {
        for (int i = 0; i < date.month - 1; i++) {
            sum += pn[i];
        }
        sum += date.day;
    }
    return sum;
}
int main() {
    Date d;
    while (cin >> d.year >> d.month >> d.day) {
        cout << countDay(d)<<endl;
    }
}