GATE 2018 Previous Year Paper Solution Question 3 – Computer Science

In this video questions which were asked in the exam of GATE 2018 are solved.

Question :- 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, the dequeue be implemented by the 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)

Solution is explained in the video.