Delete a linked list between two nodes (singly and doubly)

deleteBetween.cpp

void deleteList(node* cur);

// Doubly linked list
node* deleteBetween(node* head, node* x, node* y) {
    if (x->prev)
        x->prev->next = y->next;
    else
        head = y->next;
    if (y->next)
        y->next->prev = x->prev;
    y->next = nullptr;
    deleteList(x);
    return head;
}

void deleteList(node* cur) {
    while (cur) {
        node* tmp = cur->next;
        delete cur;
        cur = tmp;
    }
}

// Singly linked list
node* deleteBetween2(node* head, node* x, node* y) {
    node dummy; dummy.next = head;
    node* cur = &dummy;
    while (cur->next != x) cur = cur->next;
    cur->next = y->next;
    if (y->next) y->next->prev = x->prev;
    y->next = nullptr;
    deleteList(x);
    return dummy.next;
}