题解 | #打印日期#

#include <iostream>
#include <cstdio>
using namespace std;

int daytab[2][13] = {
	{0,31,28,31,30,31,30,31,31,30,31,30,31},
	{0,31,29,31,30,31,30,31,31,30,31,30,31}
};
bool IsLeapYear(int year) {
	return (year % 4 == 0 && year % 100 != 0 || year % 400 == 0);
}
int main() {
	int year, month, day;
	int number;
	std::cin >> year >> number;
	month = 0;
	int row = IsLeapYear(year);
	while (number > daytab[row][month]) {
		number -= daytab[row][month];
		month++;
	}
	day = number;
	printf("%04d-%02d-%02d", year, month, day);
}