#include <stdio.h>
struct date
{
    int year;
    int month;
    int day;

}st;
void f(int day);
void main()
{
    struct date st;
    enum weekday{sun,mon,tue,wed,thu,fri,sat}day;
    //int i;
    for(day=sun;day<=sat;day++)
        printf("%d",day);
}
   
    printf("plase input year:");
    scanf("%d",&st.year);
    printf("plase input month:");
    scanf("%d",&st.month);
    printf("plase input day:");
    scanf("%d",&st.day);
    if(st.month==1||st.month==2)
    {
        st.month+=12;
        st.year--;
    }
       day=(enum weekday)(st.day+2*st.month+3*(st.month+1)/5+st.year+st.year/4-st.year/100+st.year/400)%7;
    f(day);
}
void f(day)
{
  
    switch(day)
    {
    case(0):printf("星期一\n");break;
    case(1):printf("星期二\n");break;
    case(2):printf("星期三\n");break;
    case(3):printf("星期四\n");break;
    case(4):printf("星期五\n");break;
    case(5):printf("星期六\n");break;
    case sun:printf("星期日\n");break;
    }

}
怎么让case 里面的是sun,而不是6呢