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About the test:

The Data Structures Test evaluates a candidate's understanding of fundamental data structures such as arrays, linked lists, stacks, queues, trees, and graphs. It assesses their knowledge of various data structures operations, algorithms, and problem-solving skills. The test includes multiple-choice questions to assess theoretical knowledge and coding questions to evaluate practical implementation.

Covered skills:

  • Array
  • Stack
  • Tree
  • Hashing
  • Searching
  • LinkedList
  • Queue
  • Graph
  • Sorting
  • Recursion

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9 reasons why
9 reasons why

Adaface Data Structures Assessment Test is the most accurate way to shortlist Software Engineers



Reason #1

Tests for on-the-job skills

The Data Structures Test helps recruiters and hiring managers identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves time by filtering out unqualified candidates at the first step of the hiring process.

The test screens for the following skills that hiring managers look for in candidates:

  • Ability to implement and manipulate arrays efficiently
  • Understanding and implementation of linked lists
  • Proficiency in stack operations and concepts
  • Ability to handle queue operations and understand its principles
  • Familiarity with tree data structures and its traversal techniques
  • Knowledge of graph data structure and its algorithms
  • Understanding of hashing techniques and its applications
  • Proficiency in sorting algorithms and their time complexities
  • Knowledge of searching techniques and their implementations
  • Understanding and application of recursion in problem-solving
Reason #2

No trick questions

no trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

View sample questions

The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface
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Reason #3

Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

How we design questions

These are just a small sample from our library of 10,000+ questions. The actual questions on this Data Structures Test will be non-googleable.

🧐 Question

Hard

Graph Traversal and Data Storage
Graph Theory
Algorithm Analysis
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Consider the following pseudo code implementing a specific graph traversal algorithm:
 image
What is the order in which the nodes are processed, and which data structure best represents the graph `G` for efficient traversal?

Medium

Implementing a Browser's Back Button
Stack
Data Handling
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You are tasked with implementing the "Back" button functionality in a web browser. This feature allows users to return to previously visited web pages in the order they were viewed. The browser maintains a history of URLs in a data structure. Considering the nature of web browsing, where users can go back multiple steps and then navigate to a new page (at which point the future history should be cleared), which data structure and algorithm would best implement this functionality?
A: Use a heap, add the current URL when navigating to a new page, and remove the top element when the back button is used.
B: Use a queue, enqueue the current URL when navigating to a new page, and dequeue when the back button is used.
C: Use a single stack, push the current URL when navigating to a new page, and pop when the back button is used.
D: Use an array, add the current URL to the end when navigating to a new page, and remove the last URL when the back button is used.
E: Use a linked list, add the current URL to the head when navigating to a new page, and move backwards when the back button is used.
F: Use two stacks, push the current URL to the first stack when navigating to a new page, and use the second stack to store the pages when the back button is used.

Easy

Linked List Element Removal
Linked Lists
Element Removal
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Consider a singly linked list where each node contains an integer value. Write a function `removeElement` that removes all occurrences of a specific value from the linked list. The function should return the head of the modified linked list.

Pseudo code:
 image
What will be the content of the linked list referred to by `result` after executing the above pseudo code?

Easy

Registration Queue
Logic
Queues
Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.
For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.
⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
5
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10

Medium

Visitors Count
Strings
Logic
Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 
Example:

Input:
WWMMWWCCC

Expected Output: 
4W3C2M

Explanation: 
‘W’ has the highest count, then ‘C’, then ‘M’. 
⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.
🧐 Question🔧 Skill

Hard

Graph Traversal and Data Storage
Graph Theory
Algorithm Analysis

3 mins

Data Structures
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Medium

Implementing a Browser's Back Button
Stack
Data Handling

2 mins

Data Structures
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Easy

Linked List Element Removal
Linked Lists
Element Removal

2 mins

Data Structures
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Easy

Registration Queue
Logic
Queues

30 mins

Coding
Solve

Medium

Visitors Count
Strings
Logic

30 mins

Coding
Solve
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Graph Traversal and Data Storage
Graph Theory
Algorithm Analysis
Data Structures
Hard3 mins
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Implementing a Browser's Back Button
Stack
Data Handling
Data Structures
Medium2 mins
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Linked List Element Removal
Linked Lists
Element Removal
Data Structures
Easy2 mins
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Registration Queue
Logic
Queues
Coding
Easy30 minsSolve
Visitors Count
Strings
Logic
Coding
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

customers in 75 countries
Brandon

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!


Brandon Lee, Head of People, Love, Bonito

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Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment Data Structures Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Science behind Adaface tests
Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the Data Structures Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

invite candidates
Reason #7

Detailed scorecards & benchmarks

View sample scorecard
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Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

test completion rate
Reason #9

Advanced Proctoring


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About the Data Structures Online Test

Why you should use Pre-employment Data Structures Test?

The Data Structures Test makes use of scenario-based questions to test for on-the-job skills as opposed to theoretical knowledge, ensuring that candidates who do well on this screening test have the relavant skills. The questions are designed to covered following on-the-job aspects:

  • Ability to implement and work with Array data structures
  • Knowledge of LinkedList data structure and its operations
  • Proficiency in implementing and utilizing Stack data structure
  • Understanding of Queue data structure and its applications
  • Familiarity with Tree data structure and various traversal techniques
  • Knowledge of Graph data structure and common algorithms like Dijkstra's and BFS
  • Understanding and utilization of Hashing in solving data structure problems
  • Proficiency in various sorting algorithms and their time complexities
  • Knowledge of searching algorithms like binary search and their optimizations
  • Understanding and application of recursion in solving problems

Once the test is sent to a candidate, the candidate receives a link in email to take the test. For each candidate, you will receive a detailed report with skills breakdown and benchmarks to shortlist the top candidates from your pool.

What topics are covered in the Data Structures Test?

  • Array

    Array is a data structure that stores a fixed-size sequence of elements of the same type. It allows for efficient random access and modification of elements. The skill of working with arrays is measured in this test to evaluate the candidate's ability to manipulate and optimize data storage and retrieval using this fundamental data structure.

  • LinkedList

    LinkedList is a data structure that consists of a series of nodes, each containing an element and a reference to the next node. It provides efficient insertion and deletion operations in comparison to arrays. This skill is assessed to gauge the candidate's understanding of dynamic memory allocation and their ability to implement and use linked lists for various applications.

  • Stack

    Stack is an abstract data type that follows the Last-In-First-Out (LIFO) principle. It supports two primary operations: push, which adds an element to the top of the stack, and pop, which removes the topmost element. This skill is tested to assess the candidate's knowledge of stack-based algorithms and their ability to implement stack-based solutions for problems.

  • Queue

    Queue is an abstract data type that follows the First-In-First-Out (FIFO) principle. It supports two primary operations: enqueue, which adds an element to the end of the queue, and dequeue, which removes the frontmost element. This skill is measured in the test to evaluate the candidate's familiarity with queue-based algorithms and their proficiency in implementing queue-based solutions for various problems.

  • Tree

    Tree is a hierarchical data structure consisting of nodes connected by edges. It has a single root node and can have a varying number of child nodes. The skill of working with trees is assessed in this test to evaluate the candidate's ability to understand and implement tree-based algorithms like traversals, searching, and balancing.

  • Graph

    Graph is a non-linear data structure composed of a set of nodes (vertices) and a set of edges that connect these nodes. It is used to represent relationships between objects and entities. Testing the skill of working with graphs helps measure candidates' understanding of graph algorithms like traversal, shortest path, and connectivity.

  • Hashing

    Hashing is a technique that converts a given data item into a unique index value using a hash function. It allows for efficient retrieval and storage of data by minimizing the searching time. This skill is measured in the test to evaluate the candidate's ability to implement and use hash-based data structures, such as hash tables and hash maps.

  • Sorting

    Sorting is the process of arranging elements in a specific order, such as ascending or descending. It is an important skill to assess as sorting algorithms are fundamental for various applications. Evaluating the candidate's proficiency in sorting algorithms helps determine their ability to efficiently organize data.

  • Searching

    Searching is the process of finding a particular element(s) in a given collection of data. It is crucial for information retrieval and decision-making. Assessing the candidate's skill in searching algorithms helps identify their ability to locate and retrieve data efficiently across different data structures.

  • Recursion

    Recursion is a programming technique where a function calls itself to solve a problem by breaking it into smaller sub-problems. It allows for elegant and concise code solutions but requires proper understanding and handling to avoid infinite loops. Testing the skill of recursion helps evaluate the candidate's ability to think recursively and solve complex problems efficiently.

  • Full list of covered topics

    The actual topics of the questions in the final test will depend on your job description and requirements. However, here's a list of topics you can expect the questions for Data Structures Test to be based on.

    Array insertion
    Array deletion
    Array searching
    Array sorting
    Linked list creation
    Linked list traversal
    Linked list insertion
    Linked list deletion
    Stack operations
    Queue operations
    Binary tree creation
    Binary tree traversal
    Binary tree insertion
    Binary tree deletion
    Graph representation
    Graph traversal
    Graph shortest path
    Graph cycle detection
    Hashing techniques
    Hash functions
    Hash table operations
    Bubble sort
    Selection sort
    Insertion sort
    Merge sort
    Quick sort
    Binary search
    Linear search
    Binary search tree creation
    Binary search tree traversal
    Binary search tree insertion
    Binary search tree deletion
    Recursion basics
    Recursive algorithms
    Recursive data structures
    Recursive backtracking
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What roles can I use the Data Structures Test for?

  • Software Engineer
  • Data Analyst
  • Web Developer
  • Software Tester
  • Computer Programmer
  • IT Freshers

How is the Data Structures Test customized for senior candidates?

For intermediate/ experienced candidates, we customize the assessment questions to include advanced topics and increase the difficulty level of the questions. This might include adding questions on topics like

  • Ability to design and implement efficient algorithms with given requirements
  • Knowledge of complexity analysis and ability to optimize code for performance
  • Proficiency in implementing data structures using object-oriented principles
  • Understanding of memory management techniques and efficient memory usage
  • Familiarity with various types of trees like binary search trees and AVL trees
  • Knowledge of graph algorithms like topological sorting and minimum spanning trees
  • Ability to handle large datasets and efficiently process data
  • Understanding and utilization of dynamic programming in problem-solving
  • Proficiency in using various data structures to solve real-world problems
  • Knowledge of trade-offs between different data structures and their use cases

The coding question for experienced candidates will be of a higher difficulty level to evaluate more hands-on experience.

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The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.


85%
reduction in screening time

Data Structures Hiring Test FAQs

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify. Here's a quick guide on how you can request a custom test.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

  • Non-googleable questions
  • IP proctoring
  • Screen proctoring
  • Web proctoring
  • Webcam proctoring
  • Plagiarism detection
  • Secure browser
  • Copy paste protection

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

Yes, you can sign up for free and preview this test.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

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