题解 | 日期累加

#include<stdio.h>
using namespace std;
int daymonth[13] = { 0,31,29,31,30,31,30,31,31,30,31,30,31 };
int isleapyear(int year)
{
	return(year % 4 == 0 && year % 100 != 0 || year % 400 == 0);
}
int main()
{
	int num;
	scanf("%d", &num);
	for (int i = 0; i < num; i++)
	{
		int year, month, day, add;
		scanf("%d %d %d %d", &year, &month, &day, &add);
		if (isleapyear(year))
		{
			daymonth[2] = 29;
		}
		else daymonth[2] = 28;
		add += day - 1;
		day = 1;
			while (add > daymonth[month])
			{
				if (isleapyear(year))
				{
					daymonth[2] = 29;
				}
				else daymonth[2] = 28;
				add = add - daymonth[month++];
				if (month > 12)
				{
					month = 1;
					year++;
				}
			}
			day += add;
	
		printf("%4d-%02d-%02d\n", year, month, day);
	}
	return 0;
}