Understanding pointers in sample program

Question

I am having issues understanding pointers in C++. I thought I understood, but after this practice, it seems to be a challenge.

int main() {
        int x, y, z;
        int *p =&x, *q = &y, *r =&z;
        *p = 7;
        *q=4;
        *r = (x+y) * 4;
        *p=*q;
        x = (*q) + (*r);
        p=q;
        q=r;
        *r=*p;
        y = (*r * 3) +y;
        cout<<x << " " << y << " " << z<<endl;
        cout<< *p<<" " << *q << " " << *r<< endl;
        return 0;
    }

My thought process: p and x = 7, q and y = 4. and r and z = 44. Then p = q so x = 4. Then we change x to 48. Now when p=q and q=r, I am not sure what happens. Can anyone assist me to understand? Thank you

Answer 1

     +-----+
p -> |  x  |
     +-----+
     +-----+
q -> |  y  |
     +-----+
     +-----+
r -> |  z  |
     +-----+

p = q

     +-----+
     |  x  |
p    +-----+
 \   
  \  +-----+
   ->|     |
   ->|  y  |
  /  |     |
 /   +-----+
q
     +-----+
r -> |  z  |
     +-----+

q = r     

     +-----+
p    |  x  |
 \   +-----+
  \  +-----+
   ->|     |
     |  y  |
     +-----+
q
 \
  \  +-----+
   ->|     |
   ->|  z  |
  /  |     |
 /   +-----+
r

Answer 2

p=q assigns to p pointer the value of q pointer which is the address of y, so after this assignment p actually points to y.

The other part is similar.