c语言编写程序计算日期是当年的第几天 定义一个结构体变量（包括年、月、日）。计算该日在本年中是第几天，注意闰年问题

#include <stdio.h>

struct Date {
    int year;
    int month;
    int day;
};

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

int calculateDayOfYear(struct Date date) {
    int daysInMonth[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int dayOfYear = 0;
    
    for (int i = 1; i < date.month; i++) {
        dayOfYear += daysInMonth[i];
    }
    
    dayOfYear += date.day;
    
    if (isLeapYear(date.year) && date.month > 2) {
        dayOfYear += 1;
    }
    
    return dayOfYear;
}

int main() {
    struct Date date;
    
    printf("请输入日期（年 月 日）：");
    scanf("%d %d %d", &date.year, &date.month, &date.day);
    
    int dayOfYear = calculateDayOfYear(date);
    
    printf("该日在本年中是第%d天\n", dayOfYear);
    
    return 0;
}