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About the test:

The Data Structures Test assesses candidates’ knowledge of core data structures, OOPs fundamentals & proficiency in developing systems and applications using appropriate data structures.

Covered skills:

  • Computer fundamentals
  • Queues
  • Stacks
  • Trees
See all covered skills

9 reasons why
9 reasons why

Adaface Data Structures 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.

The Adaface Data Structures Online Test screens candidates for the typical skills recruiters look for Software Engineer roles:

  • Knowledge of core data structures like the Stack, Queues, Trees, Graphs, LinkedList, Hash Maps
  • Understanding of OOPs fundamentals
  • Proficiency in developing systems and applications using appropriate data structures
  • Experience with various sorting algorithms (bubble sort, merge sort, shell sort, etc.)

The insights generated from this assessment can be used by recruiters and hiring managers to identify the best candidates for Software Engineer roles. Anti-cheating features enable you to be comfortable with conducting assessments online. The Data Structures Online Test is ideal for helping recruiters identify which candidates have the skills to do well on the job.

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.

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 ->
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.

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


What does the following pseudo code print?


Fibonacci codes
Time Complexity
Pseudo Code
Here are three pseudocodes for calculating the Nth Fibonacci number. Which of the following statements about these codes are true?
A: Time complexity/efficiency of CODE 1, CODE 2, CODE 3 is the same.
B: CODE 2 is more space-efficient than CODE 3.
C: CODE 3 is more space-efficient than CODE 2.
D: CODE 2 is more time-efficient than CODE 1.
E: CODE 3 is more time-efficient than CODE 1.


Palindrome Test cases
Go through the following faulty palindrome detection pseudocode and test cases. For which of the test cases would the code return true?
A: a
B: aba
C: aaa
D: aac


Rewards Activities Order
Database Connection
A new popular app tracks the activities performed by its users and grants them rewards based on each individual's total activities performed in a year. This data is maintained in a database table (activitesinfo), with the following columns: userid, totalactivities, reward. This year, due to fundraising activity, the company has decided to further reward its users by enhancing the reward as per the following formula: If reward < = 4000, increase it by 2%, If 4000 < reward <= 8000, increase it by 4%, If reward > 8000, increase it by 6%.
The tech team has written three different scripts to calculate increment for each slab, each script is to run as a separate transaction. Here are the three scripts:
Script 1:
For users with reward <= 4000, set reward = reward * 1.02

Script 2:
For users with reward > 4000 and reward <= 8000, set reward = reward * 1.04

Script 3:
For users with reward > 8000, set reward = reward * 1.06
Each script is to be executed separately. Which of the following options will update the rewards as expected:
A: Execute Script 1 followed by Script 2 followed by Script 3
B: Execute Script 2 followed by Script 3; Script 1 running concurrently throughout
C: Execute Script 3 followed by Script 2; Script 1 running concurrently throughout
D: Execute Script 3 followed by Script 2 followed by Script 1
E: Execute Script 2 followed by Script 3 followed by Script 1
🧐 Question🔧 Skill


2 mins
Technical Aptitude


Fibonacci codes
Time Complexity
Pseudo Code
2 mins
Technical Aptitude


Palindrome Test cases
2 mins
Technical Aptitude


Rewards Activities Order
Database Connection
3 mins
Technical Aptitude
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Technical Aptitude
Medium2 mins
Fibonacci codes
Time Complexity
Pseudo Code
Technical Aptitude
Hard2 mins
Palindrome Test cases
Technical Aptitude
Hard2 mins
Rewards Activities Order
Database Connection
Technical Aptitude
Medium3 mins
Reason #4

1200+ customers in 75 countries

customers in 75 countries

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

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.

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

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

About Software Engineer Roles

A data structure is a particular way of storing data in a computer that allows one to make efficient use of it. In one way or another, most commercial systems use different types of data structures.

Data structures are a type of data organization, maintenance, and storage format that aids many organizations in accessing and changing data efficiently. It is also the foundation for an abstract data form (ADT). Data structures are a set of algorithms that can be used in any programming language to organize data in memory.

Typical Software Engineer responsibilities include:

  • Designing, developing, and managing high-volume, low-latency software programs
  • Analyzing user requirements to inform application design
  • Defining application objectives and functionality by working closely with other development teams, UX designers, business and systems analysts
  • Supporting users by developing documentation and assistance tools
  • Implementing quality assurance procedures

What roles can I use the Data Structures Test for?

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

What topics are covered in the Data Structures Test?

Linear Data Structures
Circular Singly Linked List Insertion
Special Stack Data Structure
Binary Search Tree
Fibonacci Heap
Separate Chaining For Collision Handling
Self Organizing List
Binary Indexed Tree
Kasai’s Algorithm
LRU Cache
Cartesian Tree
Strassen’s Matrix Multiplication
Singly Linked List
Doubly Linked List
Handshaking Lemma
Order Statistics In BST
Heap Sort
Open Addressing For Collision Handling
Unrolled Linked List
Two Dimensional Binary Indexed Tree Or Fenwick Tree
Ukkonen’s Suffix Tree
Decision Trees
Gomory-Hu Tree
Expression Tree
Linked List Insertion
The Great Tree-List Recursion
Priority Queue
BFS Vs DFS For Binary Tree
Binary Heap
Tournament Tree (Winner Tree)
Graph, Directed Graph, Undirected Graph, And Directed Acyclic Graph
Segment Tree And Persistent Segment Tree
Suffix Array And Suffix Tree
Avl Tree, Splay Tree, B Tree, Red-Black Tree, And K Dimensional Tree
Spaghetti Stack
Tree Traversal
Circular Linked List
Threaded Binary Tree
Binomial Heap
Skip List
Suffix Array Nlogn Algorithm
Ternary Search Tree
B+ Tree
Singapore government logo

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.

reduction in screening time


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.

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
  • Web proctoring
  • Webcam proctoring
  • Plagiarism detection
  • Secure browser

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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