Linked Lists: A Comprehensive Guide for Online Learning

Question 1

Consider a linked list with n nodes. Which operation on this linked list has a time complexity of O(n)?

Accepted Answer

Traversing the list from the start to the end

Answer

Inserting a node at the beginning of the list

Answer

Deleting a node from the middle of the list

Question 2

In a linked list, how are nodes managed in terms of memory allocation and deallocation?

Accepted Answer

Nodes are dynamically allocated as required and freed when no longer referenced by other nodes.

Answer

Nodes are allocated in a continuous memory block and freed when the list is destroyed.

Answer

Nodes are statically allocated at compile time and cannot be freed.

Question 3

Which fundamental data structure in computer science allows elements to be stored non-contiguously in memory?

Accepted Answer

Linked List

Answer

Queue

Answer

Stack

Answer

Array

Question 4

How does a linked list differ from an array in terms of memory allocation?

Accepted Answer

Elements in a linked list can be scattered throughout memory, while elements in an array are stored contiguously.

Answer

Linked lists require more memory than arrays.

Answer

Arrays can only store primitive data types, while linked lists can store both primitive and complex data types.

Question 5

What is the time complexity of finding an element in a singly linked list?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(n^2)

Answer

O(log n)

Question 6

What is the purpose of a head node in a linked list?

Accepted Answer

To provide a starting point for traversing the list

Answer

To store the size of the list

Answer

To store the data of the first element

Answer

To mark the end of the list

Question 7

How does a doubly linked list differ from a singly linked list?

Accepted Answer

Each node in a doubly linked list has both a next and a previous pointer, while each node in a singly linked list has only a next pointer.

Answer

A doubly linked list can only store objects, while a singly linked list can only store primitive data types.

Answer

A doubly linked list is always circular, while a singly linked list is always linear.

Question 8

What is the definition of a circular linked list?

Accepted Answer

A linked list where the last node points to the first node, forming a circular structure.

Answer

A linked list where each node contains a reference to itself.

Answer

A linked list where the nodes are arranged in a random order.

Question 9

Which algorithmic approaches can be used to reverse a linked list?

Accepted Answer

Both iterative and recursive algorithms

Answer

Dynamic programming algorithms

Answer

Greedy algorithms

Answer

Divide-and-conquer algorithms

Question 10

Which of the following accurately describes a linked list?

Accepted Answer

A linear data structure where nodes are connected sequentially

Answer

A data structure that is inherently more efficient than arrays

Answer

A hierarchical data structure that can represent complex relationships

Answer

A data structure where elements are stored in contiguous memory locations

Question 11

What is the primary function of a head node in a linked list?

Accepted Answer

To point to the first node in the list

Answer

To store the data value of the first node

Answer

To keep track of the size of the list

Answer

To mark the end of the list

Question 12

What defines a doubly linked list?

Accepted Answer

A linked list where each node has pointers to both the previous and next nodes

Answer

A linked list where nodes are arranged in a circular fashion

Answer

A linked list that is sorted in ascending order

Answer

A linked list that uses recursion to navigate its nodes

Question 13

Which of the following is NOT an application of linked lists?

Accepted Answer

Implementing arrays

Answer

Representing sparse matrices

Answer

Managing memory efficiently

Answer

Storing hierarchical data

Question 14

What is the time complexity of traversing a singly linked list from start to end?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(n^2)

Answer

O(log n)

Question 15

What is the key characteristic of a circular linked list?

Accepted Answer

The last node points back to the first node, forming a loop

Answer

Each node contains a reference to itself

Answer

The first node points back to the last node

Answer

The list is sorted in descending order

Question 16

What is the primary advantage of using a linked list over an array?

Accepted Answer

Dynamic memory allocation, allowing for flexible list size

Answer

Faster access time to specific elements

Answer

Improved cache performance

Answer

Reduced storage space requirements

Question 17

Which technique can be used to implement a linked list in a programming language that lacks native linked list support?

Accepted Answer

Using explicit pointers to connect nodes dynamically

Answer

Employing template metaprogramming

Answer

Relying solely on dynamic memory allocation

Answer

Implementing object-oriented principles

Question 18

Define a linked list.

Accepted Answer

A linear data structure where elements are connected through pointers.

Answer

An array-based data structure where elements are accessed using indices.

Answer

A non-linear data structure where elements are organized in a tree structure.

Question 19

What key advantage do linked lists have over arrays?

Accepted Answer

Dynamic memory allocation, allowing insertion and deletion of elements without shifting.

Answer

Smaller memory footprint compared to arrays.

Answer

Faster search time due to direct access to elements.

Question 20

Identify an operation that can be performed in constant time in a singly linked list.

Accepted Answer

Adding an element to the beginning of the list.

Answer

Inserting an element in the middle of the list.

Answer

Searching for an element by its value.

Answer

Deleting an element from the end of the list.

Question 21

What is the defining characteristic of a circular linked list?

Accepted Answer

The last element points back to the first element, creating a loop.

Answer

Elements are sorted in ascending or descending order.

Answer

Elements are stored in a circular buffer.

Question 22

Describe a doubly linked list.

Accepted Answer

Each node has pointers to both the previous and next nodes.

Answer

Nodes are stored in a doubly balanced tree.

Answer

Nodes are stored in a two-dimensional array.

Question 23

Which linked list operation has a worst-case time complexity of O(n)?

Accepted Answer

Searching for an element by its value.

Answer

Deleting an element from the end of the list.

Answer

Adding an element to the beginning of the list.

Answer

Inserting an element in the middle of the list.

Question 24

Explain the purpose of a sentinel node.

Accepted Answer

Marks the beginning or end of a linked list, simplifying operations.

Answer

Points to itself.

Answer

Contains a null value.

Question 25

What is an advantage of a doubly linked list over a singly linked list?

Accepted Answer

Easier insertion and deletion of elements in the middle of the list.

Answer

Faster search time due to direct access to elements.

Answer

Smaller memory footprint compared to singly linked lists.

Question 26

Describe a common way to implement a queue using linked lists.

Accepted Answer

Use two pointers, one pointing to the front and one to the rear of the queue.

Answer

Use a doubly linked list with a dummy node.

Answer

Use a singly linked list with a circular reference.

Question 27

What is the main advantage of using a linked list over an array?

Accepted Answer

Dynamic Memory Allocation

Answer

Efficient for sorting data

Answer

Faster insertion and deletion operations

Question 28

Which of the following is NOT a common type of linked list?

Accepted Answer

Circular Queue

Answer

Doubly Linked List

Answer

Circular Linked List

Answer

Singly Linked List

Question 29

In a singly linked list, what does the 'next' pointer of the last node point to?

Accepted Answer

NULL

Answer

The previous node

Answer

The first node

Answer

The node containing the list's size

Question 30

You want to insert a new node at the beginning of a singly linked list. Which of the following steps would you take?

Accepted Answer

1. Set the new node's 'next' pointer to the current head. 2. Update the head to point to the new node

Answer

1. Find the last node. 2. Set the last node's 'next' pointer to the new node

Question 31

What is the time complexity for searching for a specific element in a singly linked list?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(n log n)

Answer

O(log n)

Question 32

Which of the following operations is typically more efficient in a linked list compared to an array?

Accepted Answer

Insertion at a specific position

Answer

Sorting the data

Answer

Searching for a specific element

Answer

Random access to elements

Question 33

A doubly linked list differs from a singly linked list because it:

Accepted Answer

Has 'next' and 'previous' pointers in each node

Answer

Allows for faster searching

Answer

Requires less memory

Answer

Is more efficient for sorting

Question 34

You want to delete a node from a singly linked list. What is the first step in this process?

Accepted Answer

Find the node to be deleted and its preceding node

Answer

Set the 'next' pointer of the deleted node to NULL

Answer

Update the head pointer to point to the next node

Question 35

In a circular linked list, what does the 'next' pointer of the last node point to?

Accepted Answer

The first node

Answer

NULL

Answer

The node containing the list's size

Answer

The previous node

Question 36

What is the primary advantage of using a linked list over an array for storing data?

Accepted Answer

Linked lists offer dynamic memory allocation, allowing them to grow or shrink as needed

Answer

Linked lists are faster for random access than arrays

Answer

Linked lists are more efficient for storing large amounts of data

Question 37

In a linked list node, what is the purpose of the 'next' pointer?

Accepted Answer

It connects to the subsequent node in the list, defining the order.

Answer

It holds the data value associated with the node.

Answer

It points to the preceding node in the list.

Question 38

Between a singly linked list and a doubly linked list, which is typically faster for forward traversal?

Accepted Answer

Singly linked list

Answer

Doubly linked list

Answer

Insertion at the beginning.

Answer

Deletion of a node in the middle.

Question 39

You need a data structure that efficiently adds and removes items at both the beginning and end. Which is the most suitable choice?

Accepted Answer

Doubly linked list

Answer

Array

Answer

Singly linked list

Answer

Stack

Question 40

What is the time complexity of inserting a new node at the beginning of a singly linked list?

Accepted Answer

O(1)

Answer

O(log n)

Answer

O(n)

Answer

O(n^2)

Question 41

What characterizes a circular linked list?

Accepted Answer

The last node points back to the first node, creating a loop.

Answer

It uses head and tail pointers to manage insertions and deletions.

Answer

Each node has a pointer to its predecessor.

Question 42

To manage a queue of tasks in order, which linked list implementation is best?

Accepted Answer

Singly linked list with head and tail pointers.

Answer

Circular linked list.

Answer

Doubly linked list.

Answer

Array.

Question 43

What is the key difference between a stack and a linked list?

Accepted Answer

A stack follows the Last-In-First-Out (LIFO) principle, while a linked list allows access to any element.

Answer

A stack uses arrays, while a linked list uses pointers.