Data Structures: A Comprehensive Guide for Beginners

Question 1

Which of the following is not a fundamental data structure in computer science?

Accepted Answer

Database

Answer

Array

Answer

Linked List

Answer

Tree

Question 2

What is the time complexity of searching for an element in an unsorted array of size n?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(log n)

Answer

O(n^2)

Question 3

Which data structure is most appropriate for implementing a priority queue, where elements are processed based on their priority?

Accepted Answer

Binary Heap

Answer

Array

Answer

Stack

Answer

Linked List

Question 4

What is the primary purpose of a hash function?

Accepted Answer

To map elements to specific storage locations

Answer

To generate unique keys for elements

Answer

To sort elements in ascending order

Answer

To optimize memory usage

Question 5

What is the worst-case time complexity of inserting an element into a balanced binary search tree?

Accepted Answer

O(log n)

Answer

O(1)

Answer

O(n)

Answer

O(n^2)

Question 6

In Java, which class implements a dynamic array?

Accepted Answer

java.util.ArrayList

Answer

java.util.List

Answer

java.util.Collection

Answer

java.lang.Array

Question 7

In a linked list, what is the time complexity of searching for an element?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(log n)

Answer

O(n^2)

Question 8

What is the primary function of a hash table?

Accepted Answer

Storing key-value pairs efficiently

Answer

Maintaining data in sorted order

Answer

Representing hierarchical relationships

Answer

Searching for elements in large datasets with high efficiency

Question 9

Which data structure is best suited for implementing a queue?

Accepted Answer

Linked list

Answer

Array

Answer

Tree

Answer

Graph

Question 10

Differentiate between stacks and queues. Which one operates on a Last In First Out (LIFO) principle?

Accepted Answer

Stacks follow LIFO, while queues follow FIFO (First In First Out).

Answer

Queues follow LIFO, while stacks follow FIFO.

Answer

Stacks and queues are identical data structures.

Answer

Queues are inherently more efficient than stacks.

Question 11

In a balanced binary search tree, what condition must be met at all nodes?

Accepted Answer

The difference between left and right subtree heights is at most 1.

Answer

All leaves are at the same level.

Answer

The number of nodes in the left subtree equals the number in the right subtree.

Answer

The sum of values in the left subtree equals the sum in the right subtree.

Question 12

Inserting an element into a red-black tree has a time complexity of:

Accepted Answer

O(log n)

Answer

O(1)

Answer

O(n)

Answer

O(n^2)

Question 13

What is the intended purpose of a minimum spanning tree?

Accepted Answer

Identifying a subset of edges that connect all nodes with minimum total weight

Answer

Finding the shortest path between two nodes in a graph

Answer

Finding the path with minimum cost between two nodes in a graph

Answer

Finding the longest path between two nodes in a graph

Question 14

Describe the primary distinction between a circular linked list and a singly linked list. Illustrate a scenario where a circular linked list offers advantages.

Accepted Answer

A circular linked list connects its last node to its first node, forming a loop, while a singly linked list ends with a null pointer.

Answer

Both circular and singly linked lists use nodes with a single pointer.

Answer

Circular linked lists allow traversal in one direction only, while singly linked lists permit traversal in both directions.

Answer

Circular linked lists are not necessarily more memory-efficient than singly linked lists.

Question 15

Which data structure lets you easily add or remove items anywhere within it?

Accepted Answer

Linked List

Answer

Array

Answer

Tree

Question 16

Which of the following data structures stores elements in a contiguous block of memory?

Accepted Answer

Array

Answer

Linked List

Answer

Queue

Answer

Tree

Question 17

Which data structure consists of nodes connected linearly, where each node contains data and a reference to the next node?

Accepted Answer

Linked List

Answer

Stack

Answer

Tree

Answer

Array

Question 18

Which data structure effectively organizes data into a hierarchical tree-like structure, allowing for efficient representation of relationships?

Accepted Answer

Tree

Answer

Array

Answer

Hash Table

Answer

Graph

Question 19

Which operation is commonly associated with a stack data structure, involving both adding and removing elements?

Accepted Answer

Push/Pop

Answer

Insert/Delete

Answer

Enqueue/Dequeue

Answer

Add/Remove

Question 20

Which data structure efficiently associates key-value pairs, enabling rapid retrieval of data based on the provided key?

Accepted Answer

Hash Table

Answer

Array

Answer

Tree

Answer

Linked List

Question 21

Which of the following is a primary advantage of utilizing arrays as a data structure?

Accepted Answer

Efficient random access

Answer

Dynamic resizing

Answer

Efficient handling of duplicate values

Answer

Support for hierarchical relationships

Question 22

Which data structure is commonly employed to represent a sequence of elements that can be traversed sequentially?

Accepted Answer

Linked List

Answer

Array

Answer

Tree

Answer

Hash Table

Question 23

In an unsorted linked list, which operation typically exhibits a time complexity of O(n)?

Accepted Answer

Search

Answer

Traversal

Answer

Insertion

Question 24

Which data structure is well-suited for modeling hierarchical relationships, such as file systems and organizational structures?

Accepted Answer

Tree

Answer

Linked List

Answer

Queue

Answer

Graph

Question 25

Which aspect of hash tables can pose challenges and require careful consideration during implementation?

Accepted Answer

Collision handling

Answer

Efficient lookup

Answer

Ordered storage

Question 26

What is the time complexity of searching for an element in a singly linked list, assuming no additional information is available?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(n^2)

Answer

O(log n)

Question 27

Which type of tree is a hierarchical data structure where each node has a maximum of two child nodes and is commonly used for efficient searching and sorting?

Accepted Answer

Binary tree

Answer

B-tree

Answer

Red-black tree

Answer

AVL tree

Question 28

What is the purpose of a hash table?

Accepted Answer

To store and retrieve key-value pairs efficiently using a hash function to map keys to memory addresses

Answer

To sort a list of elements

Answer

To search for elements in an array

Answer

To implement queues

Question 29

Which data structure is specifically designed for storing a collection of unique elements and supports efficient addition, removal, and membership checking?

Accepted Answer

Set

Answer

Queue

Answer

List

Answer

Map

Question 30

What is the key difference between a stack and a queue data structure?

Accepted Answer

A stack follows a Last-In-First-Out (LIFO) order, while a queue follows a First-In-First-Out (FIFO) order

Answer

A stack is a linear data structure while a queue is a circular data structure

Answer

A stack can have multiple child nodes while a queue has only one

Question 31

Which operation is not supported by a binary search tree?

Accepted Answer

Inserting an element at a specific index

Answer

Searching for an element

Answer

Deleting an element

Answer

Finding the maximum element

Question 32

What is the time complexity of deleting the root element from a heap?

Accepted Answer

O(log n)

Answer

O(1)

Answer

O(n^2)

Answer

O(n)

Question 33

Which sorting algorithm has a time complexity of O(n^2) and repeatedly compares and swaps adjacent elements until the list is sorted?

Accepted Answer

Bubble sort

Answer

Quick sort

Answer

Merge sort

Answer

Heap sort

Question 34

What is the purpose of a disjoint-set union data structure?

Accepted Answer

To represent a collection of disjoint sets and efficiently perform union and find operations to determine set membership and connectivity

Answer

To implement a priority queue

Answer

To search for elements in a graph

Question 35

Which data structure stores elements that can be accessed directly using an index?

Accepted Answer

Array

Answer

Linked List

Answer

Tree

Answer

Queue

Question 36

Which data structure allows for the efficient insertion and deletion of elements anywhere in the structure?

Accepted Answer

Linked List

Answer

Stack

Answer

Array

Answer

Hash Table

Question 37

Which data structure stores hierarchical data in a tree-like structure?

Accepted Answer

Tree

Answer

Queue

Answer

Array

Answer

Linked List

Question 38

Which array operation has O(1) time complexity?

Accepted Answer

Access an element using an index

Answer

Searching for an element

Answer

Deleting an element from the middle

Answer

Inserting an element at the beginning

Question 39

Which data structure supports constant-time addition and removal of elements from one end?

Accepted Answer

Queue

Answer

Array

Answer

Tree

Answer

Linked List

Question 40

Which data structure stores key-value pairs for efficient data retrieval?

Accepted Answer

Hash Table

Answer

Tree

Answer

Array

Answer

Linked List

Question 41

Which data structure is an example of a recursive data structure?

Accepted Answer

Tree

Answer

Queue

Answer

Array

Answer

Linked List

Question 42

Which data structure is most suitable for storing a large collection of elements that require sorting?

Accepted Answer

Array (utilizing appropriate sorting algorithm)

Answer

Tree

Answer

Queue

Answer

Linked List

Question 43

Which operation is not supported by a linked list?

Accepted Answer

Direct access to element by index

Answer

Inserting an element at any point

Answer

Deleting an element from any point

Answer

Traversing the list

Question 44

Which data structure is most suitable for maintaining a collection of elements in a specific order, allowing efficient insertion and deletion at both ends?

Accepted Answer

Doubly Linked List

Answer

Array

Answer

Queue

Answer

Stack

Question 45

Consider the following linked list: 10 -> 20 -> 30 -> 40. Which operation would insert the element '25' after the node with value '20'?

Accepted Answer

Create a new node with value '25' and make it the next node of the node with value '20'.

Answer

Delete the node with value '20' and insert '25' in its place.

Answer

Create a new node with value '25' and make it the previous node of the node with value '20'.

Question 46

In a binary search tree, which property ensures that all nodes in the left subtree have values less than the root, and all nodes in the right subtree have values greater than the root?

Accepted Answer

Binary Search Tree Property

Answer

Complete Binary Tree Property

Answer

Sorting Property

Answer

Height-Balancing Property

Question 47

What is the average time complexity of searching for an element in a sorted array using a binary search algorithm?

Accepted Answer

O(log n)

Answer

O(n)

Answer

O(1)

Answer

O(n^2)

Question 48

Which data structure would be most appropriate for representing a collection of related items that can have multiple child elements?

Accepted Answer

Tree

Answer

Linked List

Answer

Array

Answer

Queue

Question 49

Which of the following data structures represents a non-linear relationship between its elements?

Accepted Answer

Graph

Answer

Queue

Answer

Array

Question 50

What is a key function used for in a hash table?

Accepted Answer

Generating a unique key for a given input.

Answer

Searching for an element in constant time.

Answer

Storing data in a specific order.

Answer

Preventing collisions in the table.

Question 51

Which of the following is a limitation of using an array as a data structure?

Accepted Answer

Fixed size.

Answer

Efficient insertion and deletion

Answer

Supports dynamic memory allocation

Answer

Easy to search