Wissen Technology conducted a recruitment drive at our campus, offering an exciting chance for students to demonstrate their abilities and secure roles in their prestigious organization.
Recruitment Overview Process
- Online Assessment
- Technical Round
- Directorial Round
Round 1: Online Assessment
Duration: 2 hours
Focus: Aptitude, DSA, and SQL assessment
Structure:
- 5 Aptitude questions
- 3 DSA questions
- 1 SQL question
Aptitude Section:
The aptitude section was quite easy and completed within 10 minutes. The questions included:
- A blood relation problem
- A problem related to time and work
- One question based on Operating Systems (OS)
- One on Java
- One related to batch processing
DSA Section:
Question 1 - String Segmentation:
Given a string, segment it into multiple parts such that no two segments contain the same repeating character.
Example: For the string "abceafg", the segments would be "abcea" and "fg" since the character 'a' repeats later in the string, we need to make a segmentation at that point.
I was able to solve this question.
Question 2 - Server Load Optimization:
Based on optimizing server load to maximize customer requests. Three arrays were given:
A[] - the number of requests made by each customer to the server
L[] - the start times of the requests
R[] - the end times of the requests
The objective was to determine the minimum value of X, which represents the minimum number of requests the server should be able to handle at any point in time, such that all customer requests are fulfilled.
Example: A = [3,4,5,6], L = [1,3,3,7], R = [5,4,8,9]
At time t = 4, the total requests being handled are:
From request 1: 3 (1 ≤ 4 ≤ 5)
From request 2: 4 (3 ≤ 4 ≤ 4)
From request 3: 5 (3 ≤ 4 ≤ 8)
Request 4 is not active at time 4
Total = 3 + 4 + 5 = 12, So the answer is X = 12.
I was able to solve this question, but I could only pass 5 out of 10 test cases. For the remaining 5, I was getting a Time Limit Exceeded (TLE) error.
Question 3 - Good Citizens:
Given an array behaviour[] which denotes the behaviour level of certain citizens. The task was to find the number of good citizens. A citizen is considered good if their behaviour level is greater than the average behaviour of their two neighboring citizens. If behaviour[i-1] or behaviour[i+1] does not exist, we assume their values to be zero.
I was able to solve this question.
SQL Section:
Given 2 tables: billing_details (procedure_id, department_id, revenue) and department_revenue (department_id, department_name).
The task was to write an SQL query to identify departments where at least one procedure has generated revenue exceeding the department's average revenue per procedure. For each qualifying department, count the number of distinct procedures that have generated above-average revenue. The output should contain the department name and the count of procedures that meet this condition. The result must be sorted in descending order by the procedure count, and in case of a tie, alphabetically by department name.
Results: Out of 385 students, 285 were eligible to take the test. Out of those, a total of 52 students were able to clear the round. The results were announced at 8 PM on the same day. I was also shortlisted for the further round.
Round 2: Technical Round
- Duration: 80-85 minutes
- Method: In-person
- Focus: DSA and SQL concepts with practical implementation
The interviewer first asked me to give a brief about myself and my interests, then took a glance at my resume before starting with DSA questions.
Key Questions:
DSA Question 1 - Word Classification:
Given a list of words, perform the following operations:
- Store all even-length words in a list
- Store all odd-length words in another list
- If an even length word has more than 5 characters, store it in another list (same for odd length)
- The lists even_longer_words and odd_longer_words should only be created if the original even or odd lists have length more than three
- The even_longer_words and odd_longer_words list should not be empty, meaning create the list on runtime, do not initialize all four lists beforehand
I was able to answer all the questions. He asked me to write the code on sheet and pseudo code for all the constraint added questions, then asked if I could think of any other solution, and the time and space complexities of the solutions I gave.
DSA Question 2 - Text Processing:
Given a multi-paragraph text:
- How will you determine that you have moved to a different paragraph while traversing the text
- Write a code to identify the paragraph with the maximum number of words
- Write a code for finding the most frequently occurring words across the entire text
- Write code for finding the most frequent palindromic words of length 4
I was able to answer all the questions and he asked me time and space complexities of the solutions I gave.
Database Design Question:
Create an ER diagram for: An author can write multiple books, a book can have multiple authors, a book can have multiple editions, and each edition will have a new ISBN number and a year. After I made the ER diagram, he asked me to explain it and asked some queries based on that ER diagram like a query to find all books written by an author, and a query to find all books having only a unique author.
Obstacles: The multiple constraints in the word classification problem required careful runtime list management, and the text processing questions needed efficient data structure selection for optimal performance.
Round 3: Directorial Round
- Duration: 60 minutes
- Method: In-person
- Focus: Problem-solving approach and system design thinking
He first asked me about myself and about the internship which I have done, then started with a DSA question.
Key Questions: DSA Question - Interview Scheduling:
Given a list of tuples such that each tuple contains a student ID and the time that student takes to complete an interview. There is a predefined time slot of 60 minutes, and you can schedule a maximum of two interviews in the slot. Which two interviews will be the most effective ones to consider?
Example: I = [(1, 30), (2, 20), (3, 50), (4, 40)]
The two best interviews would be (2, 20) and (4, 40).
I first gave the brute force solution of O(n²) and ran a few test cases, then moved to an optimal solution of O(n log n).
System Design Question:
He asked me to design the entity system for the problem: Given a directory which contains files and folders, how will you find the largest n files and folders?
I approached this as a system design question but I think it was more of a data structure design or Linux command question. I designed entities for File and Folder classes and explained the approach using heap data structure to find the top N largest items.
SQL Question:
Given two tables, one Employee and one Department table, write a query to print the maximum salary per department.
Obstacles: Moving from brute force to optimal solution required clear explanation of the trade-offs and algorithm selection reasoning.
Additional Information:
Out of 52 students who cleared the OA, nearly 30 were sent to the Directorial Round. 3 students had their Directorial Round on Monday at the office due to time constraints.
Verdict: Rejected
