Question

node *head, *current, *temp;
current = head;
while(NULL != current){
  temp = current;
  current = current->next;
}
delete current;
current = temp;
current->next = NULL;

I’m just wondering I know there’s something like this and there’s recursion, assuming there’s already a linked list and we don’t know how many nodes are in the list.

By delete I mean deallocate.

node *head, *current, *temp;
current = head;
while(NULL != current->next){
  temp = current;
  current = current->next;
}
if (NULL != current){
delete current;
current = temp;
current->next = NULL;
}

Answer 1

Your code does not do anything: the exit condition of the loop is NULL == current, meaning that delete current; will always pass NULL to delete. This is OK, but it does not de-allocate anything.

You should change your loop to stop when current->next == NULL, but you must be extra careful to make sure that you do not dereference current when it is equal to NULL:

temp = 0;
while(current && current->next){
    temp = current;
    current = current->next;
}
if (temp) {
    delete current;
    temp->next = 0;
}

EDIT : Your edited code mimics my answer to a large extent, except yours would fail if head == NULL. It would also fail if the list has exactly one node, because temp would remain unassigned.