#include <stdio.h>
typedef struct
{
   int year;
   int month;
   int day;
}date;
int days(date d)
{
    int num = 0;
    int m, da, i;
    if ((d.year %4 == 0 && d.year %100!=0)||(d.year % 400 == 0))
    {
         for (m = 1; m < d.month ; m++)
         {
              if (m == 2)
              {
                   da = 29;
                   num = num + da;
              }
              else if (m==4||m==6||m==8||m==11)
              {
                   da = 30;
                   num = num+da;
              }
              else
              {
                   da = 31;
                   num = num +da;
              }
              num = num + d.day;
        }
        return num;
   }
   else
   {
        for (m = 1; m <d.month ; m++)
        {
             if (m == 2)
             {
                  da = 28;
                  num = num +da;
             }
             else if (m==4||m==6||m==8||m==11)
             {
                  da = 30;
                  num = num +da;
             }
             else
             {
                  da = 31;
                  num = num +da;
             }
              num = num + d.day;
        }
        return num;
   }
}
int main()
{
 date d;
 scanf("%d%d%d",&d.year,&d.month,&d.day);
 printf("%d年%d月%d日 is the %d days of this year",d.year,d.month,d.day,days(d));
 return 0;
}


为什么我输入2000 2 29就能得到正确答案60
而我输入2000 3 1得到的错误答案62
这是为什么