IIT M MS CSE

GATE CS Rank - 677
GATE Score -731
Category: Gen

Direct Link to written test questions.
Syllabi for Interviews.

HI, this is Ratul Chatterjee. I have secured an AIR 677 in GATE CS 2024. I already had an AIR 738 in GATE CS 2023. So, I was quite disappointed by my performance 😕 in 2024 despite the gate score was a descent of 731. Actually, the number of students appearing this time was quite high (1.25L) due to which there were many people on same number leading to increase in ranks. Looking at the rank I wasn't confident whether I could get any of the top IITs or even IIT H or IIT BHU. So, I decided to fill the MS and MTech RA forms of old IITs.

If u have a rank between 500-2k or even 2.5k u must apply to the following programmes:

• IIT M MS (CSE, DSAI) [Both 2.5 to 3 Years]
• IIT B MTech (RA, CMinDS), MSR CSE [All 2.5 to 3 Years]
• IIT D MSR CSE, MSR Yardi AI [Both 2.5 Years], MTech HVA [3 Years] (prefers people with job)
• IIT KGP MTech AI [2 Years] (Asks questions based on your B.Tech domain like if u r from ECE they will ask from ECE field and less of AI/ML stuff)
• IIT K MSR CSE [3 Years]
• IIT H MTech RA CSE, AI [Both 3 Years]

Most of the college uses gate score as a cutoff to qualify for MS or research programmes but won't be used to evaluate results in for future rounds so u need not worry about people having higher scores than u. If u r GEN category and u have a GS of 650 and above u must apply to all of these. (For EWS 600 & above and for OBC 550 & above)

I will stick to IIT M in this blog further.

Be careful: IIT M MS in DSAI wants interview on AI and ML 
Check the syllabus here (zoom-in to see clearly) for DSAI

MS CSE GATE Score cutoff for 2024:

MS CSE criteria for 2024:

Link

[MS in DSAI had slightly less cutoff]

I had filled only CS in IIT M for MS program and then they sent us a mail which worked as a call letter for the interview. Unlike other years like 2020 - 2023 this time they called the students offline for both written test and interview as a part of the selection procedure. The syllabus for the written test was on the subjects of GATE CSE exam. the following extract is from the mail they sent us as call letter:

The written exam will be for two hours and will cover core areas of Computer Science and Engineering, including C programming, digital logic, discrete mathematics, data structures, algorithms, computer organization/architecture, theory of computation, operating systems, database management systems, compiler design, computer networks. In addition, there will be questions on analytical ability. 

But on 23rd April we all received a mail regarding a research aptitude test to be held on 25th April. It was already mentioned for DSAI guys but there was no mention of this test in the call letter mail of CSE that we received earlier. Anyways we had to appear in the exam, and they attached a list of FAQs regarding this test which i am providing underneath: 

We weren't sure whether this test was to be considered for the selection process or not as in the call letter mail, they said:

The selection process includes a written test followed by an interview. The interview will be conducted for those candidates who get shortlisted based on their performance in the written test.

Moving forward we were given sample papers on 24th April from all the 6 sessions they mentioned. Here are all the sample papers. The exam was of 1hr as per the scheduled time but there won't be any penalty even if we are able to submit within 1hr 10mins and the submission time was till 1hr 30mins but there will be some penalty after 1hr 10mins.
The paper for CSE was scheduled from 1pm and the actual paper appeared in the moodle platform from 12:45pm onwards but I was late and found that on 12:57pm. The test wasn't proctored and was a descriptive one (u can read the description of any of the question paper to get the details)

I was able to gather the actual question papers of only the CS and DSAI branches.

There was no shortlisting on the basis of this test. I have to go to IIT M now but before that I had document verification and counseling at IIT BHU, so I left for BHU from 29th April to 2nd May. My train to Chennai was from Howrah at 12 midnight on 3rd May and I will reach there on 5th May in the morning around 3am.This was going to be my first solo trip and I was quite excited. I reached the destination (Chennai Central) at 2:45 am in the night on 5th May and slept at the executive lounge until the sun rises. Then I woke up at 6 am took a shower and had some coffee and left for IIT Madras. Outside Chennai Central u will find Chennai Central metro. I took that and reached Little Mount station and from there I took a bus to IIT Madras. U can definitely ask a local where to get a bus to reach IIT. I was mesmerized by the logo at the main door until then I had only seen that in photos and YouTube videos 

Then I entered and the guards asked me the purpose of visit I showed them my call letter mail and they asked me to board the bus, with a smile, which will take to the CCW hostel which is the office of hostel management at IIT M.

The buses here cover the entire campus and after every 15 mins u can get one bus. As the campus is huge u can't go from one place to other without bus or bicycles. U can get the schedule of buses here. On the way to the hostel 

I saw monkeys, black bucks and deers in the campus and infinite trees. Then after reaching CCW, I had to wait for sometime and my hostel and mess was provided. I roamed around the campus and met a few other people who had come for the same. It was a bright hot day with a lot of humidity but was definitely a thrilling experience 

End of 5th May 

Morning of 6th May:

Woke up early as we had to attend to the CSE department for the written test from 8am. There was a whole building dedicated to computer science but too far from our hostels :( 

They took a small orientation program and then started registration process after which we had the written exam from 10 am to 12 noon

U can find the memory-based questions here.

Once the test was over, we were told to have lunch and the list of shortlisted candidates was out by 1:25pm and I was fortunate to be shortlisted. They asked the shortlisted candidates to stay over for their document verification and the rest of guys were sent off.

Review of written test: Quite easy, even after not studying anything for 3 months I was able to answer most of them correctly 

They had shortlisted 46 candidates out of 140 people who had come over! They took interview of the interested people who were willing to give that day ...I tried to delay my verification to force it to next day 😁😜

There were three panels of which u can choose atmost 2 and atleast 1 to give interview.
Panel A: Theoretical CS
Panel B: Systems
Panel C: AI-ML

At 9 pm they sent us a list of the interview slots. I had opted for Panel A and Panel C which were scheduled from 9 am to 1 pm and 2pm to 6pm on 7th April respectively. I had prepared only LA since after the GATE exam, so the Panel A was just a trial one for me and I was happy it was before the Panel C interview.

Doom's Day (7th May):

Woke up very early in the morning. I was a little worried and didn't want to lose in the finals 😅. So revised a few things of eigen values and eigen vectors. Then I went for the breakfast and rushed to the department. We were taken to the panel A within a while and were asked to sit there and fill out favorite subject which we would like to be interviewed on (they gave a list of subjects to choose from). My name came in the third and I entered the panel of 7 professors.

Panel A Interview: 

Interviewer 1: Hi Ratul, we are the TCS panel, and I can see u have chosen DSA as favorite subject.

Me: acknowledged.

Interviewer 1: So, Ratul Why u choose Panel A and not Panel B?

Me: Panel A deals with Mathematical things and I have interest in mathematics, so I decided to go with Panel A rather than B

(They looked satisfied and now real interview starts. Although I am better in systems, but the systems interview was after panel C so it kind of worked out the way I wished for😁)

Interviewer 1: Let's say u r given a board of snakes and ladders game and a regular die. We have to go from 1 to n with minimum no of dice rolls. We don't want the probability of that. Design this as a computer science problem and give me a good solution.

Me: (Thought for few minutes) Then I said we can jump by 2 steps and reach n like we do in binary search. They reminded that u cannot jump arbitrarily as the dice and ladder constraints are there else, we could jump from 1 to n directly. (Until then I was in immense pressure) They told me that u can use the board.

I went to the board drew some snakes and ladders and then I thought it looks somewhat like the Dijkstra's single source shortest path algorithm with the vertices as each cell and snakes are ignored. They weren't satisfied and wanted more concrete answered and told me u r thinking in the right direction but not 100% right. They gave a hint that there can be a snake after which there can be a ladder to the n-1 so u cannot ignore the snakes. I tried to think a lot but due to time constraint they asked which things I am good at ... I replied trees heaps BST AVL array LL but they asked me to show the algorithm of Dijkstra single source shortest path only 

Then I tried to explain the algorithm with an example, but I messed up with primary but fortunately by their hints I was able to get that

Then they asked me TC of the algorithm. There also I had messed up and they told me we will see u soon.

I knew my interview went very bad. I would have rejected myself but atleast I got an idea of what they are asking. I tried to convince myself that I haven't prepared these since last 3 months and I still have a chance in panel C.I went for the lunch thereafter and came back at 2:40 pm.

Other questions asked in panel A:

1. U r given glass bottles and u have stairs from 1 to n u have to determine the threshold of the stairs beyond which the bottle will definitely break.
2. Binary search and it's optimization. Angry Cows problem
3. Insertion in LL and deletion.
4. Find the expectation of no of local minimas in an array of n numbers.

I found the questions were quite hard rather than a few which were easy. If u r not good with coding logics, it's not suggested to go with DSA😐.My interview lasted 20 minutes some had 15 or even 25 minutes.

Panel C Interview:

I was called in like in no 4 or 5. They were randomly calling us, and I was strongly determined I have to give my best and cannot afford to lose this opportunity. I entered the panel. There were 5 professors sitting there and 3 of them were Bengali.

Interview 1: Hi Rahul (he got my name wrong like most people and I didn't say anything also 😂) so u have applied to panel A and Panel C?

Me: Yes sir 

Interviewer 1: When did u passout ?

Me: 2023

Interviewer 1: What were u doing since last one year?

Me: I was doing GATE preparation (they don't know that I got almost same rank two times😅)

Interviewer 1: So, u got a GATE score of 731 and u didn't do any job?

Me: I said no sir I was totally with preparation (forgot that I had done a 6-month internship as a content creator role for making videos and short notes related to GATE CSE)

Interviewer 1: U have a CGPA of 9.29 form which college? 

Me: Told cllg name (tier 3 cllg... mostly they don't know)

Interviewer 1: Where is it?

Me: West Bengal, Kolkata 

Interviewer 1: Since u have given interview in panel A u cannot choose the same subject again here.

Rest of the professors including me were laughing and I said I have come prepared with linear algebra. So, he asked another interviewer to start the interview and asked him to keep it only 15 minutes.

Real Interview Begins: 

[No favorite topics were asked. Started asking questions randomly]

Interviewer 2: Ratul tell me what do u mean by the span of vectors?
Me: Span means to take linear combination of a given set of vectors and generating the vectors that can be created from them. In span we usually multiply each vector by some scalar quantity and then add them up which is often termed as linear combination of vectors.

Interviewer 2: So, what will be the span of vectors in R²?
Me: (asked if I can use the board ...they said sure u can). So, I drew two non collinear vectors in R² and said if we take the span of these vectors then we can generate any vector in R² by parallelogram law of vectors.

Interviewer 2: Let's say we are in R³.When will we be able to say that we can generate any vector b in R³ ?
Me: If we put all the vectors in a matrix and apply the row reduced gauss Jordon elimination or even the gaussian elimination and we obtain 3 pivots at the end then we can generate any vector b in R³.

Interviewer 2: Can u explain in terms of Linear Independence?
Me: Yes sir ...gave the definition of Linear Independence and said if we aren't able to find any non-zero ci such that c1v1+c2v2+c3v3=0 then they will be linearly independent, and we can generate any vector in R³.

Interviewer 2: When will the span of three vectors in R³ will be a line 
Me: I was thinking I had to explain by linear independence, so I said with it.

Interviewer 2: Explain geometrically 
Me: (Took a pause then I got stroke by the answer suddenly) If all the three vectors are collinear then their span will be a line.

Interviewer 2: Let's say we have all vectors in R^d and there are such n Linearly independent vectors such that n≤d. What will be the space spanned by these vectors?
Me: n-D space in R^d

Interviewer 2: Are u familiar with eigen values and eigen vectors
Me: Yes sir 

Interviewer 2: Write down the Fibonacci series 
Me: 0,1,1,2,3,5,8,13, ...

Interviewer 2: Let's consider we have a matrix Ax=y such that x is a 2×1 column vector consisting of two consecutive numbers of the series and y is also a 2×1 column vector which are the next consecutive numbers in the series. For example, x= [0 1] ᵀ and y= [1 2] ᵀ or x=[2,3]ᵀ y=[5,8]ᵀ. Can u tell me what is A?

Me: (I borrowed 1 min from the professor then I was thinking how to obtain A. They were asking a transformation matrix for Fibonacci series, and I remembered the concepts of 5 ways to multiply matrices from Professor Gilbert Strang's videos. Then I remembered how to obtain it ...even if I can use two matrices and join them, I can get my final matrix which is the idea behind composition of Linear transformation)

https://ianthehenry.com/posts/fibonacci/

Interviewer 2: Can u say what will be A¹⁰⁰ if we are given it's eigen values?
Me: Thought for a minute (then he changed question)

Interviewer 2: So first let's find the eigen values of A?
Me: Found them.

Interviewer 2: Are any two consecutive numbers of the series an eigen vector of A?
Me: No, I guess (very hesitantly)

Interviewer 2: Why u think so?
Me: In order to be an eigen vector we need to multiply a matrix A times a vector x such that we obtain a scalar λ times the same vector x. But here every two consecutive numbers will get transformed to a new set of consecutive number and there won't be any scalar factor that can generate my old vector x.

[He looked quite satisfied and again went back to the previous question]

Interviewer 2: U r given the eigen values of A. Using them say what will be A¹⁰⁰x? [This will be your last question]
Me: (at lightning speed) λ¹⁰⁰x (I haven't understood the question before😐😅)

Interviewer 2: So that was quite fast. Okay now u have few bonus questions to answer. U have a matrix A whose eigen values u know already. I add a scalar 2 along the diagonals of this matrix. Tell me what will the new eigen values without recomputing it (assume no information about A)
Me: A+2I is the operation that is being performed (A+2I) x=Ax+2Ix=λx+2x=(λ+2) x. So, every eigen values of A can be added by 2 to obtain the new value.

Interviewer 2: Why |A-λI| =0 in case of eigen values characteristic equation?
Me:

Interviewer 2: Tell me the complexity of computing eigen values. Let me simply it, tell me the complexity of computing determinants?
Me: I think it's n².
Interviewer 2: No, it's not n² it much larger than that u can revisit it later.

Greeted goodbye and left with smiles 😁 

This interview went as per my expectations. I was quite satisfied by my performance. I went back to my hostel and then visited Marina beach with a couple of friends. Then 8th April I had my train back home. I was able to explore only 20% of the huge campus in 4 days. Flushed with greenery definitely a memorable journey to IIT M. People with high ranks must not lose hope for top colleges and keep continuing their preparation. U don't know when it's your day.

Other questions asked in Panel C interview:

1. Why we get real eigen values for a real symmetric matrix?
2. Why are the eigen vectors of a real symmetric matrix orthogonal? (answer)
3. U r given a bunch of linearly independent real eigen vectors determine the original matrix.
4. What are the applications of linear algebra and eigen values and eigen vectors?
5. What is basis? and definition of a vector.
6. What is LA? Why we don't study non-linear algebra?

Topics to study:

Entire GATE CSE syllabus for EM (LA only), Vector Spaces, Subspaces, four fundamental Subspaces, Rank and Finding the solution to system of linear equations, LU Decomposition, Determinants, Eigen Values and Eigen Vectors, Orthogonal Projection, Linear Transformation, Change of Basis, Orthogonality, Diagonalization.

Sources:

•  * Linear Algebra | Khan Academy
• Linear Algebra | Mathematics | MIT OpenCourseWare
• 3Blue1Brown
• GO Classes EM from Sachin Mittal Sir (Free for both CSE and DA syllabus)

[Please don't ask for any notes and study topics mentioned above only. It's better to follow all four resources. U can start from Sachin Sir to get the things familiar and then switch to foreign teachers]

Books (Optional):

• Gilbert Strang Edition 5 
• Solutions to Gilbert Strang
• David C. Lay Linear Algebra
• Solutions to David C. Lay
  
  

Duration Of my interview: 32 minutes (Panel C)
Verdict: Cheers Selected!

In case you have any questions use the comment section of this post: https://gateoverflow.in/blog/15846/iit-m-ms-2024 (comment section of this blog might be glitchy)

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