帮我写一个C语言日期计算器代码

好的，以下是C语言日期计算器的代码：

#include <stdio.h>

int main()
{
    int year, month, day, days;
    printf("请输入年份：");
    scanf("%d", &year);
    printf("请输入月份：");
    scanf("%d", &month);
    printf("请输入日期：");
    scanf("%d", &day);

    switch(month)
    {
        case 1:
            days = day;
            break;
        case 2:
            days = 31 + day;
            break;
        case 3:
            days = 59 + day;
            break;
        case 4:
            days = 90 + day;
            break;
        case 5:
            days = 120 + day;
            break;
        case 6:
            days = 151 + day;
            break;
        case 7:
            days = 181 + day;
            break;
        case 8:
            days = 212 + day;
            break;
        case 9:
            days = 243 + day;
            break;
        case 10:
            days = 273 + day;
            break;
        case 11:
            days = 304 + day;
            break;
        case 12:
            days = 334 + day;
            break;
        default:
            printf("输入的月份有误！\n");
            return ;
    }

    if((year % 4 ==  && year % 100 != ) || year % 400 == )
    {
        if(month > 2)
        {
            days++;
        }
    }

    printf("%d年%d月%d日是这一年的第%d天。\n", year, month, day, days);

    return ;
}

希望能够帮到你！