How to standout in a DSA Interview ? | Important tips to crack DSA Assessment Rounds | @SCALER

Summary

In this informative session, Harid Gupta from Soft Engineered discusses the best practices for tackling Data Structures and Algorithms (DSA) interviews. He emphasizes the importance of understanding the problem, starting with brute force solutions, and then optimizing them. Gupta highlights the need for clear communication of your approach, clean and understandable code, and thorough testing. Tips for preparation include practicing on a text editor, mock interviews, and being receptive to interviewer hints. The session aims to equip viewers with strategies to excel in DSA interviews.

Takeaways

• 📚 Importance of DSA: DSA rounds are crucial in the hiring process to test candidates' coding and problem-solving skills.
• 🧐 Preparation Beyond Coding: Solving many problems helps clear online assessments, but more is needed for in-person interviews.
• 🔍 Clarification First: Always clarify the problem and assumptions before diving into a solution to avoid misunderstandings.
• 🔄 Start with Brute Force: If an optimal solution is not immediately clear, start with a brute force approach to demonstrate a base understanding.
• 💡 Think Out Loud: Share your thought process with the interviewer to keep them engaged and understand your approach.
• ⏱ Time Complexity: Always consider and state the time and space complexity of your solutions to show awareness of efficiency.
• 🔄 Optimize: Be open to hints from the interviewer and optimize your solution based on feedback to show adaptability.
• 💻 Code Quality: Write clean, readable code with meaningful variable names and comments to demonstrate good coding practices.
• 📝 Dry Run: Test your code with examples and edge cases to ensure correctness and demonstrate thoroughness.
• 📈 Practice Mock Interviews: Use mock interviews to practice explaining your approach and receiving feedback for improvement.
• 🔑 Communication: Maintain open communication with the interviewer to understand their expectations and adjust your approach accordingly.

Q & A

What is the main topic of the video script?

The main topic of the video script is discussing the right way to tackle Data Structures and Algorithms (DSA) questions in interviews.

Who is the speaker in the video script?

The speaker in the video script is Harid Gupta, a mentor of Soft Engineered.

What is the purpose of the SC Master Class mentioned in the script?

The SC Master Class is designed to help individuals improve their DSA knowledge and skills with the guidance of industry-leading experts.

Why is it important to understand the problem before providing a solution in a DSA interview?

Understanding the problem is crucial because it helps to avoid misinterpretation, ensures the solution is relevant, and demonstrates the candidate's ability to work with ambiguity.

What is the difference between a DSA online assessment and a DSA interview?

An online assessment primarily checks if the code is fully optimal, functional, and passes test cases, while a DSA interview also evaluates the candidate's ability to explain their approach and write clean, readable code.

What are the steps suggested for tackling DSA questions in an interview?

The steps suggested are: 1) Clarification or disambiguation, 2) Brute force or suboptimal solutions, 3) Building an optimal solution, 4) Improving the solution, 5) Coding, and 6) Testing or dry run.

Why is it recommended to think out loud while solving a problem in an interview?

Thinking out loud allows the interviewers to follow the candidate's thought process, which is as important as the final solution itself.

What should be the time and space complexity of a solution in a DSA interview?

The solution should aim for optimal time and space complexity, which means minimizing both as much as possible while still solving the problem effectively.

How can one prepare for a DSA interview?

One can prepare by solving questions in a text editor, practicing explaining their approach, using mock interviews for feedback, and understanding the interviewer's expectations.

What is the importance of variable naming in coding during a DSA interview?

Meaningful variable names are important as they make the code easier to understand and show the candidate's attention to detail, but they should not be overly descriptive to save time.

Why is it important to test the code with edge cases during the interview?

Testing with edge cases helps to demonstrate the candidate's thoroughness and ability to handle various scenarios, which is a valuable skill in software engineering.

Outlines

00:00

📘 Interview Preparation for DSA Rounds

Harid Gupta, a mentor at Soft Engineered, introduces the video's focus on tackling DSA (Data Structures and Algorithms) interviews effectively. He emphasizes the importance of DSA rounds in the hiring process and distinguishes between online assessments and in-person interviews. Gupta suggests that while solving many problems is beneficial, additional strategies are necessary for interview success. He outlines the unique challenges of in-person interviews, such as explaining your approach and writing clean, understandable code, and the importance of recognizing and improving upon one's solutions during the interview.

05:01

🔍 Steps to Ace a DSA Interview

The video script outlines a structured approach to DSA interviews, beginning with clarification of the problem at hand. It advises candidates to take time to understand the question fully and to discuss any assumptions with the interviewer. The script then moves on to suggesting the consideration of brute force solutions as a starting point, with an emphasis on time efficiency. It encourages candidates to think out loud to demonstrate their thought process and to explain their approach clearly, including the time and space complexity of their solutions. The script also highlights the importance of improving solutions based on interviewer feedback and the final steps of coding, which should be quick and include clear comments, and concludes with a brief testing phase to ensure the code's correctness.

10:03

👨‍🏫 Practical Tips and Example for DSA Interview Success

The script provides practical tips for preparing for a DSA interview, recommending that candidates practice on a text editor to mimic the interview setting and to focus on explaining their approach and code. It suggests mock interviews for gaining experience and receiving feedback. An example problem is presented to demonstrate the discussed strategies: finding an element with more than one occurrence in an array. The example walks through clarification questions, a brute force solution, and the development of a more optimal solution using sorting or a frequency map. The script concludes by emphasizing the importance of communication with the interviewer and adapting to their expectations, reminding viewers that an interview is a discussion, not a battle.

Keywords

💡DSC questions

DSC stands for Data Structures and Coding, which refers to a set of problems related to computer science that test a candidate's ability to implement and understand data structures and algorithms. In the video, the speaker mentions having solved 500 DSC questions, indicating a deep practice in preparation for technical interviews. The speaker's confidence in cracking all the DC rounds in companies is based on this extensive preparation.

💡DC rounds

DC stands for Data Coding, which is a common term used to describe rounds in technical interviews that assess a candidate's knowledge and problem-solving ability in data structures and coding. The script emphasizes the importance of DC rounds in the hiring process and suggests that the speaker will discuss strategies to excel in these rounds.

💡Soft Engineered

Soft Engineered is mentioned as the mentor's affiliation, indicating a background in software engineering and a role in guiding and educating others in this field. The mentor's expertise is highlighted to lend credibility to the advice given in the video.

💡DSA

DSA stands for Data Structures and Algorithms, which is a fundamental area of computer science that involves the study of efficient organization, storage, and retrieval of data, as well as the development of algorithms to solve problems. The video's theme revolves around how to tackle DSA questions in interviews efficiently.

💡Online Assessment (OA)

An Online Assessment (OA) is a method used by companies to screen candidates' technical skills remotely. In the script, the difference between OAs and in-person interviews is discussed, highlighting that while both involve DSA questions, the strategies to excel in them differ, especially in terms of code readability and interaction with the interviewer.

💡Coding Interview

A coding interview is a part of the hiring process where candidates are required to write code and explain their approach to solving a problem. The script discusses expectations from candidates in a coding interview and provides steps to tackle coding questions effectively.

💡Clarification

Clarification in the context of the video refers to the initial step in the problem-solving process where a candidate ensures they fully understand the problem statement. The script emphasizes the importance of taking time to clarify ambiguities in the problem before attempting a solution.

💡Brute Force Solution

A Brute Force Solution is a straightforward approach to solving a problem, often not the most efficient but serves as a starting point. The script mentions this as a step where if an optimal solution isn't immediately apparent, one should propose a brute force solution and then look to optimize it.

💡Optimal Solution

An Optimal Solution is a solution that provides the best outcome in terms of time and space complexity. The video script discusses the importance of thinking of an optimal solution during an interview, as it demonstrates a candidate's ability to balance efficiency and effectiveness.

💡Pseudo Code

Pseudo Code is a high-level description of an algorithm that does not contain the strict syntax of a programming language but explains the steps in plain language. The script suggests using pseudo code as a way to explain one's approach to the interviewer.

💡Time and Space Complexity

Time and Space Complexity are measures of the efficiency of an algorithm, indicating how the execution time and memory usage scale with the size of the input data. The script advises candidates to always state the time and space complexity of their solutions to show their understanding of these efficiency factors.

💡Variable Naming

Variable Naming refers to the practice of assigning meaningful names to variables in code to improve readability and understanding. The script emphasizes the importance of using meaningful variable names instead of generic ones like 'x', 'y', 'z' to make the code more understandable.

💡Dry Run

A Dry Run is a practice of testing code with sample inputs to ensure it works as expected without writing the full test cases. The script advises candidates to perform a quick dry run to demonstrate their code's correctness and to adjust if any issues are found.

💡Mock Interviews

Mock Interviews are practice interviews conducted to help candidates prepare for real interviews. The script recommends using mock interviews as a way to get feedback and improve interview skills, especially in explaining approaches and coding under time constraints.

Highlights

Harid Gupta, a mentor at Soft Engineered, discusses the effective approach to tackle DSA questions in interviews.

The importance of DSA rounds in the hiring process and the expectations from candidates in coding interviews.

The difference between DSA online assessments and in-person interviews, emphasizing the need for code readability and explanation.

Clarification or disambiguation as the first step in tackling a DSA interview question.

The strategy to start with a brute force solution and then optimize it in the interview.

The necessity of thinking out loud during the interview to demonstrate the thought process.

The importance of stating time and space complexity of any solution proposed during the interview.

Improving solutions based on hints from the interviewer and demonstrating the ability to optimize.

Coding efficiently during the interview, with tips on commenting and variable naming for clarity.

The significance of a dry run to test the code on given inputs and edge cases.

Preparing for a DSA interview by solving questions in a text editor and practicing explanations.

The value of mock interviews for practice and receiving feedback on interview performance.

An example problem demonstration on finding an element with more than one occurrence in an array.

The process of clarification for the example problem, including handling negative numbers and sorted lists.

Exploring different approaches like sorting, frequency maps, and hash sets for the example problem.

Writing clean and efficient code for the example problem, with emphasis on variable naming and comments.

The final advice on maintaining communication with the interviewer to understand their expectations.

The conclusion summarizing the key points for excelling in DSA interviews and inviting further questions.

Transcripts

I have solved 500 DSC questions I'm

definitely going to crack all the DC

rounds in all the companies

right right well maybe you need

something more hello everyone this is

harid Gupta a mentor of soft engineered

Google today I will be discussing with

you what is the right way to tackle DSA

cions in any interview but before we

talk about that check out SC Master

Class by industry leading experts only

on scalers event page link is in the

description below so today we are going

to discuss how to answer any DSA problem

in an interview efficiently DSA rounds

are one of the most common and most

important rounds in any company's hiring

process DSA round or coding or problem

solving or algorithms round many names

similar expectations these rounds are

meant to test your DC knowledge problem

solving ability but not just that

today we are going to discuss what are

the expectations from a candidate in a

coding interview we will discuss what is

the right way to answer in your coding

round and how to

prepare I know many of you will say that

they know how to prepare just do a lot

of problems and yes that will help you

improve your DSN knowledge and your

coding skills this kind of preparation

will help you clear the OA for the

companies but to perform well in an

in-person interview you'll need a bit

more this is why often we see people who

are very good at coding not doing so

well in the interviews so how DSA OA is

different than DSA interview some

companies first take an online

assessment round for DSA and then an

interview even though both rounds are

similar and the questions that are asked

are mostly similar but the strategy to

excel in these rounds are different the

OA round or online assessment round just

covers whether your code is fully

optimal fully functional and passes the

test cases very rarely it happens that

someone is actually going to look at

your code or actually going to read that

code and check how readability is but in

OA the problem is that there's not much

room for errors but that's not the case

with d interviews even if you're not

very sure about some language construct

you can mention to the interviewer that

I don't remember the exact way this

thing is implemented but you can tell

them how it

works what makes a DSA inter view

slightly difficult or just different

maybe is that you have to explain your

approach and your code it's not just

about having the right approach but also

being able to explain your approach

properly and writing the code that's

clean readable and easily understandable

here we are not running our code on some

test cases so we have to check ourself

if our code is correct if it's covering

all the Hedge cases and it's the most

optimal possible

in many cases the interviewer might not

tell you if your code is covering all

edge cases or if the time and space

complexity can be improve so you have to

demonstrate the skills to realize if

your solution is the most optimal or if

it can be improved much like actual

software engineering

work so how should we tackle CS in a

dcent interview follow these steps so

step one clarification or disambiguation

clarify the question first you have

enough time so you can take a few

minutes to understand the question

properly a lot of times people panic and

just start talking about an approach

without actually understanding the

problem take your time understand the

problem if it's not clear maybe ask the

interview for an example if it's not

already provided in some cases the

question is intentionally left ambiguous

to evaluate the candidate's

understanding of the problem and a part

of expectations is to see if the

candidate is able to work with

ambiguity even if you're assuming

something about the problem it's a good

idea to First discuss with the

interviewer your assumptions and ask if

they have any comment on that step two

brute force or suboptimal Solutions if

you can't think of any optimal solution

right away you can start with a Brute

Force solution but don't waste a lot of

time on that just mention what will be

the Brute Force solution and provide the

reason why you're thinking of doing

something better like the solution you

provided can have a exponential time

complexity you can just mention the

approach by saying that since the time

complexity here is too high I will try

to find a better solution or maybe

optimize this one again time is crucial

here so don't spend a lot of time here

the only reason to do this is to show

the interview that while you're thinking

of a solution you do have one root Force

solution in mind it also demonstrates

that you are not just thinking about

without solving a question but solving

it optimally step three build a solution

the next step is to think of a good

optimal solution this is where your DSA

skills will be needed you can take some

time to think about the solution but a

good idea is to think out loud as the

interviewers are also interested in your

thought process being mute for a long

time will also take away their attention

not what you want in an interview while

thinking of a solution you can use an

example to build your approach and

explain your approach to the interviewer

explaining your approach by running the

steps on an example is a good way to

keep the interview aligned with your

thought process some candidates also

prefer writing algorithm or steps or

pseudo code to explain the solution this

is a personal choice and depending on

time and practice you can do it either

way also always State the time and space

complexity of any solution you're

thinking of right away don't wait for

the interviewer to ask that this shows

that while building a solution you're

keeping the time and space complexity in

mind and trying to build an optimal

solution step four improve your solution

use

hints if the provided solution isn't

most optimal or if there's something

wrong with the approach the interviewer

might hint you towards that just

remember that everything that's coming

out of the interviewer's mouth is useful

it could be a hint on how to optimize

your solution or interviewer might be

nudging you away from a bad approach so

be open to hints and try to make good

use of them a good idea is to only go to

coding when the interviewer is satisfied

if the interviewer hints you that they

are satisfied only then move towards the

coding in cases where the question might

be a little too complicated or

challenging even if you not able to

complete the code the interviewer might

still give you a good rating given that

your approach was correct and you

explained it properly step five coding

now we talk about the favorite part of

the candidates the code I generally keep

around 30 to 40% of the total time for

this part after you have formalized your

approach coding should be quick while

writing code keep talking about what

each part of the code is doing adding

some small comments here and there is a

good idea but don't start writing the

whole documentations as you have limited

time keep the comments short short and

crisp keep your code clean and easily

readable make use of spacing new lines

blocks properly to group and separate

various parts of your code variable

naming is another important thing try to

avoid naming your variables with random

words like x y z although using IG for

Loop variables is fine we all do that

for Meaningful data values it's a good

idea to have some meaningful names that

show what this variable is storing the

names don't need to be too descriptive

though as writing long descriptive names

again and again also takes time also

don't take too much time in variable

name engineering they don't have to be

perfect but just not random step six

testing or dry run as a last step test

your code dry run it on a given inputs

first and try to do it quickly if the

input is input example is not given to

you you can create a small example and

try to run it on that you don't need to

write a lot of details just enough to

demonstrate what you are doing also try

testing your code on edge cases like

empty array negative values zero sorted

array reverse sorted array Etc whatever

might be the case for the problem but

again don't spend too much time on this

part don't dedicate more than a few

minutes to dry run try to do it quickly

and in a way that interviewer also

understands what you're trying to do if

you see any problem fix fix that quickly

in some cases you might not get enough

time to dry run but that's fine too also

don't go towards a dry run if your

interviewer is trying to take you to a

follow-up question or a different

question because going to that follow-up

question or next question is more

important so now let's discuss how to

prepare for a DSA interview you know for

DSA and for coding you can do a lot of

problems and you'll improve your DSA and

coding skills but how to prepare for a

DSA inter view I'll share a few

tips try to solve a few questions on a

text editor first not an ID a text

editor okay try to mimic the interviewer

setting maybe even talk as if you are in

an interview and you're explaining your

code to someone practice explaining your

approach practice writing your approach

and demonstrating as if you are

explaining it to someone before running

test cases in an ID try to First keep

your code in a text editor look at it

yourself and try try to find any

problems or improvements in your code

when you feel that's the best you can do

then go for testing your code in an ID

one of the best ways to practice is

using mock interviews ask someone who

has some experience conducting

interviews to take your mock interview

and then ask for their feedback ask what

would be the rating if this was an

actual interview and what would be the

detailed feedback now we will

demonstrate whatever we learned today

with an example

let us consider this question given an

array find an element that has more than

one occurrence that means we have to

find an element that is

repeated let's first go towards the

clarifying questions the clarifying

questions can here be can we have

negative numbers can we have more than

one number which has a frequency more

than one and if that's the case which

one to return is the list given to a

sorted and if there are no repeated

elements what to do what to return

right after the clarification we'll try

the Brute Force solution The Brute for

solution here will be that for each

element I'll check all the elements in

the array and I'll find the same value

with a different index if there's any

such case I'll just return that number

the time complexity for this solution is

order of n Square because for each

number I'm checking the whole array

space complexity although will be order

of fun because I'm not using any extra

space here I know the solution is is

most optimal as the time complexity is

quadratic and I feel we can do better

than

that then we will build a solution I

think we can sort the list and check if

any two adjacent numbers are the same if

that's true we say that element is

repeated the time complexity for this

algorithm will be order of n login as

sorting algorithms take order of n login

time plus order of end time for AR

traversal so overall time complexity

will be order of n log n space

complexity here will be order of fun

because we are not using any extra space

another approach is frequency map what

we can do is for each number we can we

can maintain a frequency map and for

each number we can maintain a count of

how many times this number appears in

the array if we find any number which

has a frequency more than one we can

return that number or we can also

maintain a set of numbers we have seen

so far and if we encounter a number that

we have already seen which is done that

right we can use a hash set or a hashmap

here for quick checking so the time

complexity here will be order of n since

checking in a hash map or a hash set

takes order of one time space complexity

here will be order of n because we might

need to store all the numbers we can

also mention the space time tradeoff

then we can write the code which will be

straightforward here after we have

clarified the approach so this is the

code in the end one important thing to

note is that every interviewer is

different while some interviewers might

be looking for an optimal approach

others might be interested in how clean

your code is a good idea is to keep

communicating with your interviewer to

understand what they are looking for

remember an interview is supposed to be

a discussion not a vior so that's all

for today I hope I was able to help you

on how to excel in DSA interviews and

provide some useful information if you

have any further doubts please put them

in the comments below and we will be

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