Comment as to why as well.

The following code shows the enqueue() and dequeue() operations implemented using a double- linked list. The doubly-linked list used here DOES NOT have dummy head and tail nodes. Fill in the missing code to complete the methods. void Queue:: enqueue (int x) { int Queue:: dequeue () { QueueNode* toRemove = this ->tail; ----- = new QueueNode (x); int to Return = toRemove->value; new Node->next = this->head; ---------- = toRemove->previous; newNode->previous = this->tail->next = NULL; --- = new Node; - - - - - - - - - - - - - - - - - - - - - - I EVVIVUL E - - - - - - - - - - - - - - - - - - - - this->head = new Node