//初始化随机种子    //timeval是个结构体，里边有俩个变量，一个是以秒为单位的，一个是以微妙为单位的     unsigned rand_seed = (unsigned)(now.tv_sec*1000 + now.tv_usec/1000);    //都转化为毫秒     srand(rand_seed);         for (int i=0; i<10; i++) {        int _rand = rand()%100;     //产生0~99的随机数        //int _rand2 = random()%100;        log("%d", _rand);    }