Q. A queue is implemented using a non-circular singly linked list. The queue has a head pointer and a tail pointer, as shown in the figure. Let n denote the number of nodes in the queue. Let enqueue be implemented by inserting a new node at the head, and dequeue be implemented by deletion of a node from the tail.
Which one of the following is the time complexity of the most time-efficient implementation of enqueue and dequeue, respectively, for this data structure?
(A) θ(1), θ(1) (B) θ(1), θ(n) (C) θ(n), θ(1) (D) θ(n), θ(n)
Ans: θ(1), θ(n)