//指向指针的指针
    int num = 520;
    int *p = #
    int **pp = &p;
    printf("num:%d\n", num);
    printf("num:%d\n", *p);
    printf("num:%d\n", **pp);

    //打印地址进行二重验证
    printf("&p :%p\tpp:%p\n", &p,pp);
    printf("&num :%p\tp:%p\t*pp:%p\n", &num,p,*pp);