那天是一年的第几天？

按如下函数原型用函数编程解决如下的日期转换问题（要求考虑闰年的问题）：
输入某年某月某日，计算并输出它是这一年的第几天。

int  DayofYear(int year, int month, int day);
输入提示信息："Please enter year, month, day:"
输入格式："%d,%d,%d"
输出提示信息和格式："yearDay = %dn"

#include
int  DayofYear(int year, int month, int day);
int main()
{
	int year, month, day;
	long int DAY = 0;
	printf("Please enter year, month, day:");
	scanf("%d,%d,%d", &year, &month, &day);
	
	DAY = DayofYear(year, month, day);
	
	printf("yearDay = %dn", DAY);
	return 0;
}

int  DayofYear(int year, int month, int day)
{
	int  i;
	long int DAY = 0;
	int a[2][12] = {{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
					{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
	
	if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
		{
			DAY = day;
			for (i = 0; i < month - 1; i++)
			{
				DAY += a[0][i];
			}
		}
	else 
		{
			DAY = day;
			for (i = 0; i < month - 1; i++)
			{
				DAY += a[1][i];
			}
		}
	return DAY;
}

如有不足之处，还请各位大佬指点