#include<stdio.h>

int days_of_year(int year, int month, int day);

int main()

{

    int year, month, day;

    int days;

    printf("请输入三个数字：");

    while (scanf("%d%d%d", &year, &month, &day) != EOF)

// scanf 是c语言获取用户输入字符的函数，

    {

        days = days_of_year(year, month, day);

        printf("%4d-%02d-%02d是这一年中的第%d天.\n\n", year, month, day, days);

    }

    return 0;

}

int days_of_year(int year, int month, int day)

{

    int n=0;

    int i;

    int x[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };

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

        x[1] = 29;

    for (i = 0; i < month-1; i++)

        n = n + x[i];

    return n + day;

}

#--------------- 结果 ------------#

2022 8 1

2022-08-01是这一年中的第213天.