int mark[100],overn(0),i;                           
    double aver(0);
    srand((unsigned)time(NULL));
    for (i=0;i<100;i++)
    {
        
        mark[i] = int(rand()%101);
        aver += mark[i];
    }
    aver=aver/100;
    for(i=0;i<100;i++)
        if(mark[i]>=aver)
            overn++;
与

    int mark[100],overn(0),i;
    double aver(0);
   
    for (i=0;i<100;i++)
    {
        srand((unsigned)time(NULL));
        mark[i] = int(rand()%101);
        aver += mark[i];
    }
    aver=aver/100;
    for(i=0;i<100;i++)
        if(mark[i]>=aver)
            overn++;
两者的区别的原因是什么？