SinglyLinkedListNode* reverse(SinglyLinkedListNode* llist) { SinglyLinkedListNode* prev = NULL; SinglyLinkedListNode* current = llist; SinglyLinkedListNode* next = NULL;

while (current != NULL) {
    next = current->next;
    current->next = prev;
    prev = current;
    current = next;
}
return prev;

}