Question

Consider a QUEUE implemented by doubly linked cells, and containing N elements. The DEQUE operation has worst-case time complexity of...

a. O(1)
b. O(log N)
c. O(N)
d. O(N²)

Answer 1

The DEQUE operation in a QUEUE implemented by a doubly linked list has a worst-case time complexity of O(1), as it only involves updating pointers and does not depend on the number of elements.

Step-by-step explanation:

When considering a QUEUE implemented as a doubly linked list, the DEQUE operation typically means removing an element from either the front or the back of the queue. In a doubly linked list, each node has pointers to both its previous and next nodes. This allows for efficient addition and removal of elements at both ends.

The worst-case time complexity of the DEQUE operation in this scenario is O(1), which means it is a constant time operation. This is because no matter how many elements (N) are in the queue, the operation requires only a few steps: updating the pointers of the neighboring nodes and possibly updating the front or back pointers of the queue itself.