Gate rank : 201
Pre exam preparations :
I started the preparation in August 2017, first of all i checked the complete gate syllabus, and then i arranged the standard books (that were given in "What to read series" by bikram sir). Then i had to decide the order of subjects to be covered. At that point i had some of the following points in my mind :
1. I can follow one of two strategies - tough subjects last or tough Subjects first. I decided to go with tough subjects last, because i didn't wanted to loose motivation at the starting of preparation itself. (You can go with any strategy, it's just your convenience, there's no pros and cons of any of them).
2. I knew some of the subjects which when covered in series will give some advantage. Like C programming, Data structure and Algorithms should be done together. Another is TOC and Compiler. And also digital logic and computer organisation.
3. And i was suggested not to leave Maths for the end. So i had to start maths in the beginning and Complete it first or i can also do it side by side. I decided to do it side by side (reason was that i was comfortable with mathematics and i needed some break after some days of studying a particular subject). So i decided to do maths on weekends.
I started covering subjects one by one and preparing short notes while covering the subjects. Once a subject was completed, revised complete subject and then practised only previous year gate questions from go pdfs. While doing previous years many new techniques, tricks, concepts and ways of solving questions were discovered, i appended all of them in my notes. Again revised the subject and moved on to next subject.
Coming to the weekend schedule, the strategy for maths was same. In the weekend, I also revised the work done in the weekdays.
When the whole syllabus was done, i completed a full revision and two rounds of previous years. And then finally a full round of revision.
After that i gave test series. I found that subject wise tests were only a wastage of time. So i only gave full length mock tests. Best test series i found out were GO and madeeasy. The one thing i kept in mind while giving test series was that, test series are not for assessing our potential (on basis of marks) but test series are used for time management and forming the proper strategy for giving the main exam. I must tell you that i never got good marks in any of the tests but i gave good time to assess the tests and my performance. And worked on the mistakes i performed.
In the last seven days i revised once the whole syllabus, gave one test on the last fourth day and relaxed on the day before the exam.
When the results were out i knew i had to prepare for interview because there was a very narrow chance of getting into an old iit.
Interview preparation :
For interview preparations, i read 30-40 interview experiences and found out the following facts :
1. You have to prepare Algorithms and maths properly, there's a very high chance in every institute thst questions will be framed from.these subjects.
2. You have to prepare two core subjects strongly because interviewing professor will ask you your favourite subjects. So you must be prepared for that.
Keeping these things in mind, i selected DS, Algo and operating systems as my strong subjects. I covered almost every relevant proof from CLRS. practised the applications of various data structures and also covered the correctness of algorithms properly. Did almost the same thing in maths also. For OS, i read galvin again and also referred some of the PDFs of various universities for concept clarification. I also revised whole of the gate syllabus again for a safe side. And at last practised all of the previous year questions again because in written tests of various institutes all of the subjects were covered.
Interview experiences :
IITK Mtech/MS :
For both the courses there was a common written and programming test. For the written test, we had a choice of doing one of two sections : theory (maths and algo) or systems (all other subjects). I selected theory because i prepared maths and algo very well. The questions were good and many of them were not from the gate syllabus so I recommend you to check out and go through the syllabus given by them. I expected nearly 24 marks out of 30. Systems part was easy.
In programming two very easy questions were present, one was to find the second max element in array and other was traversing the string and extracting all 14 base characters and return the equivalent decimal number obtained by appending all the extracted characters. Almost everyone completed the questions in the given time. The process for mtech was over with this. But the candidates for MS had to wait for another day to appear for the interview.
In the interview they asked my favourite subject. I told them algorithms. These questions were asked :
Name the shortest path distance algorithm (any one).
Does djikstra works on negative edge contained graph?
Does it work for graph containing negative weight cycle? Why not ?
Show the correctness of djikstra.
Which algorithm works well for graph with negative weighted cycle?
Write algo for gcd, and prove its correctness, give complexity and prove that the complexity is correct.
And the interview was over.
Result was i was waitlisted at number 4 for Mtech and at number 16 (i guess) for MS.
Edit : I am selected for IITK MTech in the third list of admissions.
Next was Iisc mtech research CDS CS :
There was a written test with five questions and they were very easy (easier than the GATE). I attempted all of them. I was shortlisted for the interview. On the written test sheet, We were asked to select the labs for which we want to appear for the interview, i selected DREAM & MARS. In the interview following questions were asked :
Show how djikstra algorithm works with example. Show its correctness.
What page replacement policies do you know. Give an example where MFU performs better than LRU. And vice versa too
Why is synchronisation required in OS, how it is achieved?
Explain producer consumer problem and write the proper code. Then they asked me to improve the code and a good discussion was done on the same topic for sometime. and the interview was done.
Next was iisc csa mtech Research:
Written test contained good questions of gate level and time was sufficient. Questions were from ds, algo, os, toc and compiler. I was selected for the interview and the questions that were asked were :
Write code for merging two sorted linked lists in place.
Give a representation method for a tree in which there can be variable number of children.
Where is OS stored?
What all entities are involved in a process switch? Who schedules the scheduler? Are the registers of dispatcher different from the standard registers?
How does a process communicates with the OS ?
The interview was over and we were free to leave the campus.
Results were declared and I was selected for CDS CS.
In the end i will like to give some tips to the future aspirants :
1. If you ever doubt your capabilities or any thought of failure comes to you mind, do not think about that for a long time. Leave these thoughts and focus on your preparation. Almost everyone preparing for GATE gets such thoughts but those who keep them aside are the ones who create a chance of being successful in the exam.
2. Preparation time of 6 months is also enough so don't panic thinking that you have 8 months or 10 months. But also that never means that you have to be serious only for 6 months, if you have more time, utilise that for your betterment, and that can improve your rank a lot.
3. Start coding as early as possible. It gives you an edge at many points. So, better not to be late. You may count the advantages as coding is required for placements, for gate also and coding improves your logical thinking too.
4. Do not relax if you have a rank between 150 and 800. Prepare for research interviews from the date of GATE result itself. People fail because they prepare only in the end for interviews.
And all the best to all of you :-)
Many people were asking me the reason of choosing IITK MTech over IISc CDS MTech Research. I will reveal it here because it might help you if you get in the same position. IITK Mtech was a two year course where i would have all the options to try and then to do work/specialize in the domain where i am interested in. In IISc i would have been bounded to a single lab and would have to specialize in that domain only. I was from a below average class college and i was totally unaware of the available domains and my pure interest, that's why i preferred first exploring and then specializing. So, IITK MTech is my final decision and will be joining the institute shortly :)