Housing.com Devops Interview Questions, Process, and Tips

Round duration - 60 minutes
Round difficulty - Easy

It comprised of general aptitude questions and two coding questions. It was an offline test.

Q1. 
N Queens Problem
Given an integer N, find all possible placements of N queens on an N x N chessboard such that no two queens threaten each other.
Explanation:
A queen can attack another queen if they ar...read more
Ans. 
The N Queens Problem involves finding all possible placements of N queens on an N x N chessboard where no two queens threaten each other.
• Use backtracking algorithm to explore all possible configurations.

• Keep track of rows, columns, and diagonals to ensure queens do not attack each other.

• Generate and print valid configurations where queens are placed safely.

• Consider constraints and time limit for efficient solution.

• Exam...read more
Answered by AI
Add your answer
Q2. 
Sort 0 1 2 Problem Statement
Given an integer array arr of size 'N' containing only 0s, 1s, and 2s, write an algorithm to sort the array.
Input:
The first line contains an integer 'T' representing the n...read more
Ans. 
Sort an integer array containing only 0s, 1s, and 2s in linear time complexity.
• Use three pointers to keep track of the positions of 0s, 1s, and 2s in the array.

• Iterate through the array and swap elements based on the values encountered.

• Achieve sorting in a single scan over the array without using any extra space.
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

After having a technical discussion about my CV. He gave me two questions to code.

Q1. 
Ninja and Substrings Problem Statement
Ninja has to determine all the distinct substrings of size two that can be formed from a given string 'STR' comprising only lowercase alphabetic characters. These su...read more
Ans. 
Find all unique contiguous substrings of size two from a given string.
• Iterate through the string and extract substrings of size two

• Use a set to store unique substrings

• Return the set as an array of strings
Answered by AI
Add your answer
Q2. 
Cycle Detection in a Singly Linked List
Determine if a given singly linked list of integers forms a cycle or not.
A cycle in a linked list occurs when a node's next points back to a previous node in the ...read more
Ans. 
Detect if a singly linked list forms a cycle by checking if a node's next points back to a previous node.
• Traverse the linked list using two pointers, one moving one step at a time and the other moving two steps at a time.

• If the two pointers meet at any point, there is a cycle in the linked list.

• If one of the pointers reaches the end of the list (null), there is no cycle.
Answered by AI
Add your answer

Round duration - 30 minutes
Round difficulty - Easy

This was supposed to be the HR round but out of surprise the interviewer started by giving me a question to code. 
After I approached this question with the right solution he just asked about my family. After that he said to wait. After half an hour the results were announced. A total of three students were hired and I was amongst one of them.

Q1. 
Balanced Parentheses Combinations
Given an integer N representing the number of pairs of parentheses, find all the possible combinations of balanced parentheses using the given number of pairs.
Explanati...read more
Ans. 
Generate all possible combinations of balanced parentheses for a given number of pairs.
• Use recursion to generate all possible combinations of balanced parentheses.

• Keep track of the number of open and close parentheses used in each combination.

• Return the valid combinations as an array of strings.
Answered by AI
Add your answer

Round duration - 60 Minutes
Round difficulty - Easy

Q1. 
0/1 Knapsack Problem Statement
A thief is planning to rob a store and can carry a maximum weight of 'W' in his knapsack. The store contains 'N' items where the ith item has a weight of 'wi' and a value of...read more
Ans. 
Yes, the 0/1 Knapsack problem can be solved using dynamic programming with a space complexity of not more than O(W).
• Use a 1D array to store the maximum value that can be stolen for each weight capacity from 0 to W.

• Iterate through each item and update the array based on whether including the item would increase the total value.

• The final value in the array at index W will be the maximum value that can be stolen.
Answered by AI
Add your answer
Q2. 
Find the Second Largest Element
Given an array or list of integers 'ARR', identify the second largest element in 'ARR'.
If a second largest element does not exist, return -1.
Example:
Input:
ARR = [2,...read more
Ans. 
Find the second largest element in an array of integers.
• Iterate through the array to find the largest and second largest elements.

• Handle cases where all elements are identical.

• Return -1 if a second largest element does not exist.
Answered by AI
Add your answer

Round duration - 60 Minutes
Round difficulty - Easy

System Design Round

Q1. Design a system for Twitter, discussing its architecture, key components, and scalability considerations.
Ans. 
Design a scalable system for Twitter with key components and architecture.
• Use microservices architecture for scalability and fault isolation.

• Key components include user service, tweet service, timeline service, and notification service.

• Use a distributed database like Cassandra for storing tweets and user data.

• Implement a message queue like Kafka for handling real-time updates and notifications.

• Use a caching layer like ...read more
Answered by AI
Add your answer

Round duration - 30 Minutes
Round difficulty - Easy

It is just a formality

30 mins test on leetcode

Q1. What are your strengths and weaknesses?
Ans. 
I excel in problem-solving and teamwork, but I sometimes struggle with time management under tight deadlines.
• Strength: Strong problem-solving skills - I enjoy tackling complex coding challenges, like optimizing algorithms for better performance.

• Strength: Effective teamwork - I thrive in collaborative environments, having successfully led a project with cross-functional teams.

• Weakness: Time management - I occasionally u...read more
Answered by AI
Add your answer
Q2. Solve the given question using Binary trees (code given herein), and walk us through your approach.
Add your answer
Q3. Where do you see yourself in 5 years?
Ans. 
In five years, I envision myself as a lead software engineer, driving innovative projects and mentoring junior developers.
• I aim to lead a team on impactful projects, like developing scalable applications that enhance user experience.

• I plan to deepen my expertise in cloud technologies, contributing to projects that leverage AWS or Azure for better performance.

• I want to mentor junior engineers, sharing knowledge through ...read more
Answered by AI
Add your answer

There were 2 questions to test our basic coding knowledge.

Q1. Some basic introduction followed by sort 2 arrays into a single array.
Add your answer

Q1. Applications of various data structures.
Ans. 
Data structures are used in various applications like search algorithms, storage systems, and graph algorithms.
• Search algorithms like binary search use arrays and trees for efficient searching.

• Storage systems use data structures like hash tables and linked lists for organizing and accessing data.

• Graph algorithms like Dijkstra's algorithm use graphs and trees for solving complex problems.
Answered by AI
Add your answer

Q1. Some basic hr questions like tell me about yourself, what do you know about magicbricks,where do you see yourself in 5 years etc
Add your answer

Q1. Launch modes on android
Ans. 
Launch modes on Android determine how a new instance of an activity is associated with the current task.
• Standard: Creates a new instance of the activity in the task's stack

• SingleTop: If an instance of the activity already exists at the top of the stack, it will not be recreated

• SingleTask: Activity is always at the root of the task and no other activities can be on top of it

• SingleInstance: Similar to SingleTask, but the
Answered by AI
Add your answer

Questios based on Activity backstacks