题目：输入某年某月某日，判断这一天是这一年的第几天？

题目：输入某年某月某日，判断这一天是这一年的第几天？
#include<stdio.h>
int main()
{
int i;
int year, month, day,sum,leap;
printf("\nplease input year,month,day\n");
scanf_s("%d,%d,%d", &year, &month, &day);
switch(month)
{
case 1:sum = 0; break;
case 2:sum = 31; break;
case 3:sum = 59; break;
case 4:sum = 90; break;
case 5:sum = 120; break;
case 6:sum = 151; break;
case 7:sum = 181; break;
case 8:sum = 212; break;
case 9:sum = 243; break;
case 10:sum = 273; break;
case 11:sum = 304; break;
case 12:sum = 334; break;
default:printf("data error"); break;
}
sum = sum + day;
if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
leap = 1;
else
leap = 0;
if (leap == 1 && (month > 2))
sum++;
printf("It is the %dth day", sum);
system("pause");
}