int main()
{
time_t cur_time = time(0);
cout << "cur_time is:" << cur_time << endl;
char ct[32];
memset(ct,0,sizeof(ct));
sprintf(ct,"%lu",cur_time);
cout << "ct string is:" << ct << endl;
time_t tt = atoll(ct);
cout << "the end time is:" << tt << endl;
}