这是我的思路 代码不完全正确 怎么修改？
#include <stdio.h>
struct DATE
{
int year;
int month;
int day;
}date;
int main ()
{
    void find(struct DATE);
    int i = 0;
    int days = 0;
    int month_LeapYear[12] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int month_AverageYear[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
    printf ("输入年月日 ： ");
    scanf ("%d %d %d", &date.year, &date.month, &date.day);
    find (date);

    void find(struct DATE date);
    {
        if (date.year%4 == 0 || date.year%400 == 0)
        {
            for (i=0; i < date.month-1; i++)
            {
                days = month_LeapYear[i] + days;
            }
            days = days + date.day;
        }
        else
        {
            for (i=0; i < date.month-1; i++)
            {
                days = month_AverageYear[i] + days;
            }
            days = days + date.day;
        }
    }

    printf("该日是该年的第%d天\n", days);
}

谢谢 想问主函数中的find 函数只有声明的作用吗

主函数中的find函数的作用是什么