指向指针的指针

void func(int **a)
{
        int **p = a;
        *p = new int (3);
        cout<<"p="<<p<<"*p="<<*p<<"**p="<<**p<<endl;        
        
}

    int *a = 0;
      
    func(&a);
    cout<<"a="<<a<<"*a="<<*a<<endl;
    delete a;
    cout<<"a="<<a<<"*a="<<*a<<endl;