DSA Interview Quiz — Questions & Answers

Test your knowledge of core Data Structures and Algorithms (DSA) concepts with these easy DSA interview questions and answers. This quiz covers arrays, queues, linked lists, sorting, trees, and more for your DSA interview preparation.

This quiz contains 10 questions. Below is a complete reference of all questions, answer choices, and correct answers. You can use this section to review after taking the interactive quiz above.

1. Question 1: File Structure vs. Storage Structure

   Which statement best describes the difference between file structure and storage structure in data structures?

   • File structure relates to auxiliary memory while storage structure refers to main memory.
   • File structure is always faster than storage structure.
   • File structure and storage structure are exactly the same.
   • File structure is part of the CPU and storage structure is part of the GPU.
   Show correct answer

   Correct answer: File structure relates to auxiliary memory while storage structure refers to main memory.

2. Question 2: Linked List Type

   In which way can a linked list be classified based on its usage?

   • Always as a tree structure
   • Either linear or non-linear depending on its application
   • Only as a linear data structure
   • As a circular data structure only
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   Correct answer: Either linear or non-linear depending on its application

3. Question 3: Array Element Reference

   How can you reference all elements of a one-dimensional array in a program?

   • Using an indexed loop that iterates from 0 up to array size minus one
   • Through direct function calls for each element
   • By creating a new array to copy elements
   • By manually naming each element one by one
   Show correct answer

   Correct answer: Using an indexed loop that iterates from 0 up to array size minus one

4. Question 4: Dynamic Data Structures

   Which of the following is an example of a dynamic data structure that adjusts its size during runtime?

   • Dynamic array
   • Fixed-size array
   • Static variable
   • Constant
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   Correct answer: Dynamic array

5. Question 5: Meaning of Dequeue

   What is a dequeue in the context of data structures?

   • A kind of linked list only storing null values
   • A double-ended queue allowing insertions and deletions at both ends
   • A queue that always remains empty
   • A stack that allows insertions only at the top
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   Correct answer: A double-ended queue allowing insertions and deletions at both ends

6. Question 6: Queue Operations

   Which operation adds an element to the end of a queue?

   • isEmpty()
   • dequeue()
   • delete()
   • enqueue()
   Show correct answer

   Correct answer: enqueue()

7. Question 7: Merge Sort Definition

   What type of algorithm is merge sort and how does it function?

   • An algorithm that only sorts arrays with three elements
   • A linear search method used for duplicates
   • A divide-and-conquer algorithm that merges sorted lists
   • A brute force algorithm that compares every element
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   Correct answer: A divide-and-conquer algorithm that merges sorted lists

8. Question 8: Selection Sort Process

   How does selection sort organize an unsorted list?

   • By only sorting half the list at a time
   • By using random swaps to arrange elements
   • By repeatedly picking the smallest element and moving it to the front
   • By shuffling all elements at once
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   Correct answer: By repeatedly picking the smallest element and moving it to the front

9. Question 9: Applications of Graphs

   Which of the following is an application of graph data structures?

   • Printing numbers in sequence
   • Storing a single integer value
   • Adding two numbers together
   • Social network analysis representing people as vertices and friendships as edges
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   Correct answer: Social network analysis representing people as vertices and friendships as edges

10. Question 10: AVL Tree Explanation

    What property defines an AVL tree in data structures?

    • It does not allow insertion or deletion operations.
    • It only allows one element per node.
    • It always has an odd number of nodes.
    • It maintains a height difference of at most one between left and right subtrees at any node.
    Show correct answer

    Correct answer: It maintains a height difference of at most one between left and right subtrees at any node.