计算日期到天数转换

#include <stdio.h>
int main() 
{
    int year = 0;
    int month = 0;
    int day = 0;
    scanf("%d %d %d",&year,&month,&day);
    int arr[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
    int sum = 0;
    for(int i = 0; i<month;i++)
    {
        sum += arr[i];
    }
    sum += day;
    if(year%4 == 0 && year%100!=0 || year%400 == 0 && month>2)
    {
        sum++;
    }
    printf("%d",sum);
    return 0;
}