Swapping adjacent elements of linked list

Question

The below is my code to recursive swap the adjacent elements of a linked list. I am losing the pointer to every second element after the swap. The input is 1->2->3->4->5->6-

Answer 1

Using recursion:

void nodelist::swap(node** head) {
  if (!*head || !(*head)->next) return;
  node* const sw = (*head)->next;
  (*head)->next = sw->next;
  sw->next = *head;
  *head = sw;
  swap(&(sw->next->next));
}