int months[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
bool check(int date) //判断日期是否合法
{
    int year = date / 10000;
    int month = date % 10000 / 100;
    int day = date % 100;
    if(!day || month < 0 || month > 12 ) return false;
    if(month != 2 && day >months[month]) return false;
    if(month == 2)
    {
        if((year%4==0&&year%100!=0)||(year%400==0)) //闰年特判
        {
            if(day > 29) return false;
        }
        else 
        {
            if(day > 28) return false;
        }
    }
    return true;
}