Queue operations (enqueue, dequeue, front, rear) MCQs

By: Prof. Dr. Fazal Rehman | Last updated: September 20, 2024

What is a queue in data structures?

a) A data structure that allows random access
b) A data structure that follows LIFO (Last In, First Out) principle
c) A data structure that follows FIFO (First In, First Out) principle
d) A data structure that requires sorting before access
Answer: c) A data structure that follows FIFO (First In, First Out) principle
Which operation adds an element to the rear of the queue?

a) Enqueue
b) Dequeue
c) Front
d) Rear
Answer: a) Enqueue
What happens when you dequeue an element from an empty queue?

a) Queue becomes undefined
b) Queue becomes null
c) An error occurs
d) Nothing happens
Answer: c) An error occurs
What is the time complexity of the enqueue operation in a queue implemented using an array with sufficient capacity?

a) O(1)
b) O(log n)
c) O(n)
d) O(n log n)
Answer: a) O(1)
Which operation removes and returns the front element of the queue?

a) Enqueue
b) Dequeue
c) Front
d) Rear
Answer: b) Dequeue
What is the time complexity of the dequeue operation in a queue implemented using a linked list?

a) O(1)
b) O(log n)
c) O(n)
d) O(n log n)
Answer: a) O(1)
Which operation returns the front element of the queue without removing it?

a) Enqueue
b) Dequeue
c) Front
d) Rear
Answer: c) Front
What happens when you peek at the front element of an empty queue?

a) Queue becomes undefined
b) Queue becomes null
c) An error occurs
d) Nothing happens
Answer: c) An error occurs
What is the time complexity of the front operation in a queue?

a) O(1)
b) O(log n)
c) O(n)
d) O(n log n)
Answer: a) O(1)
Which of the following statements is true about queue operations?

a) Enqueue and dequeue can be performed simultaneously
b) Dequeue removes the rear element of the queue
c) Front changes the queue size
d) Enqueue can be performed only once
Answer: a) Enqueue and dequeue can be performed simultaneously
Which data structure is commonly used to implement a queue?

a) Stack
b) Array
c) Linked list
d) Tree
Answer: c) Linked list
In a queue, which operation modifies the size of the queue?

a) Enqueue
b) Dequeue
c) Front
d) None of the above
Answer: d) None of the above
What happens if you try to enqueue an element into a full queue (using an array implementation)?

a) The element is added at the rear
b) Queue becomes undefined
c) An error occurs
d) Nothing happens
Answer: c) An error occurs
Which queue operation is used to check if a queue is empty?

a) isEmpty
b) isFull
c) size
d) length
Answer: a) isEmpty
What is the space complexity of a queue operation?

a) O(1)
b) O(log n)
c) O(n)
d) O(n log n)
Answer: a) O(1)
Which of the following statements is true about the queue data structure?

a) It allows elements to be accessed randomly
b) It follows LIFO (Last In, First Out) principle
c) It is used for breadth-first search algorithms
d) It is used for depth-first search algorithms
Answer: c) It is used for breadth-first search algorithms
What is the primary limitation of using an array to implement a queue?

a) Limited capacity
b) Slow access time
c) Inefficient insertion and deletion
d) Inability to perform enqueue operation
Answer: a) Limited capacity
Which queue operation is responsible for decreasing the size of the queue?

a) Enqueue
b) Dequeue
c) Front
d) None of the above
Answer: b) Dequeue
Which queue operation can be used to reverse the order of elements?

a) Enqueue
b) Dequeue
c) Front
d) None of the above
Answer: d) None of the above
In queue operations, what does the term “rear” refer to?

a) The element at the front of the queue
b) The size of the queue
c) The element at the rear of the queue
d) The middle element of the queue
Answer: c) The element at the rear of the queue

 

Data Structures MCQs

Basic Concepts

1. Introduction to Data Structures
   • Abstract Data Types (ADT) MCQs
2. Complexity Analysis MCQs
   • Time complexity MCQs
   • Space complexity MCQs
   • Big O, Big Ω, Big Θ notations MCQs

Linear Data Structures MCQs

1. Arrays MCQs
   • One-dimensional arrays MCQs
   • Multi-dimensional arrays MCQs
   • Operations: traversal, insertion, deletion MCQs
2. Linked Lists MCQs
   • Singly linked list MCQs
   • Doubly linked list MCQs
   • Circular linked list MCQs
3. Stacks MCQs
   • Stack operations (push, pop, peek) MCQs
   • Applications of stacks (expression evaluation, recursion) MCQs
4. Queues MCQs
   • Queue operations (enqueue, dequeue, front, rear) MCQs
   • Types: Simple queue, circular queue, priority queue, deque MCQs

Non-Linear Data Structures MCQs

1. Trees MCQs
   • Binary trees MCQs
   • Binary Search Trees (BST) MCQs
   • AVL Trees MCQs
   • B-trees and B+ trees MCQs
   • Tree traversal methods (in-order, pre-order, post-order) MCQs
2. Heaps MCQs
   • Min-heap MCQs
   • Max-heap MCQs
   • Heap operations (insertion, deletion, heapify) MCQs
   • Applications of heaps (priority queues, heap sort) MCQs
3. Graphs MCQs
   • Graph representation (adjacency matrix, adjacency list) MCQs
   • Graph traversal algorithms (DFS, BFS) MCQs
   • Shortest path algorithms (Dijkstra’s, Bellman-Ford) MCQs
   • Minimum Spanning Tree (Kruskal’s, Prim’s) MCQs

Hashing MCQs MCQs

1. Hash Tables
   • Hash functions MCQs
   • Collision resolution techniques (chaining, open addressing) MCQs
   • Applications of hashing MCQs

Sorting and Searching Algorithms MCQs 

1. Sorting Algorithms MCQs
   • Bubble sort MCQs
   • Selection sort MCQs
   • Insertion sort MCQs
   • Merge sort MCQs
   • Quick sort MCQs
   • Heap sort MCQs
2. Searching Algorithms MCQs
   • Linear search MCQs
   • Binary search MCQs
   • Interpolation search MCQs

Miscellaneous

1. Memory Management in data structures MCQs
   • Dynamic memory allocation MCQs
   • Garbage collection MCQs
2. String Manipulation Algorithms MCQs
   • Pattern matching (KMP, Rabin-Karp) MCQs
   • String hashing MCQs

1. Data Structures MCQs 1
2. Data Structures MCQs 2
3. Data Structures MCQs 3
4. Data Structures MCQs 4
5. Data Structures MCQs 5
6. Stacks Solved MCQs
7. Queues MCQs
8. pointer mcqs
9. Array MCQs