C 语言 求指定一起加一天后的日期

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#pragma hdrstop

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#pragma argsused
int LeapYear_Month_SumDay[12]={31,29,31,30,31,30,31,31,30,31,30,31};//闰年数组，保存各月天数。

int main(int argc, char* argv[])
{
    int Year=0,Month=0,Day=0,NextDay=0;
    printf("pleace enter right Date(example:2005 6 27):/n");
    scanf("%d%d%d",&Year,&Month,&Day);
    NextDay=ReturnNextDay(Year,Month,Day);

    switch (NextDay)
    {
        case 0: printf("not a current date/n");
        break;
        case 1:
        if (Month==12)
        {
            Year++;
            Month=1;
        }
        else
        {
            Month++;
        }
        break;
    }
    if (NextDay!=0) printf("The you input next date is %d-%d-%d.Thank use bye bye!/n",Year,Month,NextDay);
    //getchar();
}

int IsLeapYear(int Year)
{
 if (Year%4==0)
 {
  if (Year%400) return 1;
  else
  {
   if (Year%100==0) return 0;
   else return 1;
  }
 }
 else
 {
  return 0;
 }
}

int IsCurrentDate(int Year,int Month,int Day)
{
 if ((Year<0) && (Year>9999) && (Month>12) && (Month<1) && (Day<1) &&(Day>31) )return 0;
 else return 1;
}

int ReturnNextDay(int Year,int Month,int Day)
{
 int ThisMonthSumDay;
 if (IsCurrentDate(Year,Month,Day)==1)
 {
  ThisMonthSumDay=LeapYear_Month_SumDay[Month-1];
  if (Month==2)
  {
   if (IsLeapYear(Year)==0) ThisMonthSumDay--;
  }
  if (Day<ThisMonthSumDay)
  {
   return ++Day;
  }
  else
  {
   if (Day==ThisMonthSumDay)
   {
    return 1;
   }
   else
   {
    return 0;
   }
  
  }
 }
 else
 {
  return 0;
 }

}
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