判断日期是否合法

bool check(int date)
{
    int year=date/10000,month=date%10000/100,day=date%100;
    if(day==0||month<0||month>13)return false;
    if(month!=2&&day>days[month])return false;
    if(month==2)
    {
        if((year%4==0&&year%100!=0)||year%400==0)
        {
            if(day>29)return false;
        }
        else{
            if(day>28)return false;
        }
    }
return true;
}