求解一道函数题

#include <stdio.h>

int isLeapYear;

void leap(int year)
{
    if ( ((year%4)==0 && (year%100)!=0)
        || ((year%400)==0 && (year%3200)!=0)
        || (year%172800)==0
        )
    {
        isLeapYear = 1;
    }
    else
    {
        isLeapYear = 0;
    }
}

int sum_day(int month, int day)
{
    int list[] = {0,366,335,307,276,246,215,185,154,123,93,62,32};
    if (month<1 || month>12)
    {
        return -1;
    }
    return list[month]-day+((isLeapYear&&month<3)?1:0);
}

void main()
{
    int year, month, day;
    printf("输入一个年、月、日，例如 2021 11 15\n");
    scanf("%d%d%d", &year, &month, &day);
    leap(year);
    printf("距离下一个年份还有 %d 天，今年%s闰年\n", sum_day(month, day), isLeapYear?"是":"不是");
}