7-10

#include<stdio.h>
int main(void)
{
    int day_of_year(int year,int month,int day);
    int days = day_of_year(2013,10,12);
    printf("%d",days);

    return 0;
}


int day_of_year(int year,int month,int day)
{
    int k,leap;
    int tab[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}
    };

    leap = (year % 4 == 0 && year%100!=0 || year%400==0);

    for(k = 1;k < month;k++)
        day = day + tab[leap][k];

    return day;
}