Basic Data Structures Flashcards

Which operation is used to remove an element from the front of a queue?

Answer: Dequeue

Dequeue (also called dequeue or poll) removes and returns the front element of a queue.

A stack implemented using an array of size N can hold at most how many elements before overflow occurs?

Answer: N

An array-based stack of size N can hold exactly N elements before a stack overflow condition.

What does the 'peek' (or 'top') operation on a stack return?

Answer: Returns the top element without removing it

Peek inspects the top element of the stack without modifying the stack.

Which abstract data type is most appropriate for implementing a print spooler?

Answer: Queue

A print spooler processes jobs in the order they arrive (FIFO), making a queue the natural choice.

In a deque (double-ended queue), insertions and deletions can occur at:

Answer: Both front and rear

A deque allows insertions and deletions at both the front and rear ends.

When evaluating a postfix expression using a stack, what happens when an operand is encountered?

Answer: It is pushed onto the stack

In postfix evaluation, operands are pushed onto the stack; operators pop operands and push results.

Which of the following queue variants gives highest-priority elements access before lower-priority ones regardless of arrival order?

Answer: Priority Queue

A priority queue dequeues elements based on assigned priority, not insertion order.