Need Method for Linked List

Ok,here's the code:

void apgr(){
node *tmp,*tmp2;

if (p == NULL)//goto last node
{ cout << "\nList is empty\n";
}
else
{ tmp2 = p;
while (tmp2->nxt != NULL)
{ tmp2 = tmp2->nxt;
}
tmp=tmp2;
}//tmp now points to last node

tmp2=p;

while(tmp2->nxt!=tmp){//goto beforelast node
tmp2=tmp2->nxt;
}//tmp2 now points to the beforelast node
cout << tmp2->num;

tmp->nxt=tmp;


}

This function is not yet completed, obviously, but I imagine,that it could start like that.

on an after thought...why not just reverse the values in the nodes rather than the nodes ?
Not a good idea, IMO. You should refrain from putting in such dependencies... it may work under the given conditions but kills code re-usability. Regards.

Why call the function agrp? What's wrong with reverse or invert? How am I supposed to know what "agrp" means?

I can give you pseudocode

Go linearly through nodes, and for each node:
make the next node point to the current node
// be careful with pointer modifications (temporary pointer variables are needed).

Finally, the initial pointer must points to the old last node (or to NULL if the list is empty)

Note : You should pass the p pointer as a parameter of the apgr function, not an ugly global variable!
And, the new pointer to the first node should be either returned by the function, or its modification must be reflected to the caller, using a pointer to pointer to node as parameter:
For instance, here are the two possible prototypes for your function:

void apgr(node**);

Or:

node* apgr(node*);