两日期间的天数

#include "stdio.h"

int days[2][13]={365,31,28,31,30,31,30,31,31,30,31,30,31,
                366,31,29,31,30,31,30,31,31,30,31,30,31};

int Leap(int year)        //判断是否为闰年
{
    return ( (year%400==0) || (year%4==0 && year%100!=0));
}

int Deal(int dat0,int dat1)
{
    int i,temp,sum0,sum;
    int year0,month0,day0,year1,month1,day1;
    sum0 = sum = 0;
    year0 = dat0/10000;    month0 = dat0/100%100;    day0 = dat0%100;
    year1 = dat1/10000;    month1 = dat1/100%100;    day1 = dat1%100;

    /**//*************************************************************/
    /**//* 在起始日期和终止日期在同一年                                         */
    /**//*************************************************************/
    if((year1-year0)==0)
      {
        if((month1-month0)==0)
            return (day1-day0);
        else
          {
            temp = Leap(year0);
            sum = days[temp][month0] - day0 +1;
            for(i=month0+1;i<=month1-1;i++)
                sum = sum + days[temp][i];
            sum =sum + day1;
            return sum;
        }        
    }

    /**//************************************************************************/
    /**//* 在起始日期和终止日期不在同一年                                       */
    /**//************************************************************************/
    //计算开始年剩余的天数
    temp = Leap(year0);
    sum0 = sum0 + (days[temp][month0] - day0) + 1;
    for (i=month0+1; i<=12; i++)
        sum0 = sum0 + days[temp][i];
    
    sum = sum +sum0;
    sum0 = 0;

    //计算中间年份的总天数
    for (i=year0+1;i<=year1-1;i++)
      {
        temp = Leap(i);
        sum = sum + days[temp][0];
    }

    //计算结束年过去的天数
    temp = Leap(year1);
    for(i=1;i<=month1-1;i++)
        sum0 = sum0 + days[temp][i];
    sum0 = sum0 + day1;

    sum = sum + sum0;

    return sum;
}

void main()
  {
    int dat0,dat1,sum;
    FILE *fp = NULL;
    if(fp = fopen("riqi.dat","r"))
      {
        while (fscanf(fp,"%d%d",&dat0,&dat1)==2)
          {
            if(dat0==0 && dat1==0)    break;
            sum = Deal(dat0,dat1);
            printf("天数为：%d ",sum);
        }
    }
    fclose(fp);
}