public DoublyLinkedList() {
head = new DoublyLinkedNode();
head.value = 0;
curr = head;
middle = head;
numNodesAdvanced = 0;
}
@Override
void add(int value) {
this.value = value;
curr.next = this;
curr.next.prev = curr;
curr = this;
head.prev = curr;
curr.next = head;
}
void deleteTail() {
curr.delete();
}
void deleteMiddleNode() {
middle.delete();
}
void deleteHead() {
head.delete();
}
void add(int val) {
numNodesAdvanced++;
DoublyLinkedNode node = new DoublyLinkedNode();
node.add(val);
if (numNodesAdvanced % 2 == 0) middle = middle.next;
}