题解 | 打印日期

#include<bits/stdc++.h>
using namespace std;
int year, day;
bool isLeapYear(int year) {
    return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);
}
int main() {

    while (cin >> year >> day) {
        int a[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        if (isLeapYear(year)) {
            a[2] = 29;
        }
        int month = 1;
        for (int i = 1; i <= 12; i++) {
            if (day <= a[i]) {
                printf("%d", year);
                printf("-");
                printf("%02d", month);
                printf("-");
                printf("%02d", day);
                break;
            }
            day -= a[i];
            month++;

        }
        cout << endl;
    }

}