Question$5$

Suppose you're using a singly linked list to implement the basic stack and queue operations. The list maintains references to both its head and tail nodes at all times.

Which of the following operations take O$(1)$ time? Select all that apply.

pop, where the top of the stack is the tail of the list

enqueue, where the front of the queue is the head of the list

push, where the top of the stack is the tail of the list

None of these

dequeue, where the front of the queue is the head of the list