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Secret Sauce for Clearing Interviews

“I answered all the questions in the interview ,but I don’t know why they did not select me”

-This is the usual question from most of the people who did not clear the interview.

Why someone will reject a candidate who answered all the questions correctly.If you think from company side ,you will come to know that recruiting a right candidate is a painful process.So missing a right candidate is a costlier mistake from their side.Ok then why rejection happens?

Reasons can be one of the following

As an interviewer I am listing down my observations about the candidates whom I have evaluated.

Attending interviews without preparation

Interview is not semester exam where we used to read overnight and write the exams.90% of the time you will fail in interviews if you don’t prepare well.Interview is not an exam,its an opportunity to showcase your skills.So if you don’t posses any skills what will you showcase there.


Product or Service Company

Preparation has to be different for Product and Service Company.Product companies expect you to be strong in DS and Algos irrespective of the programming languages.Most of the times they will be ok with any programming language.They look for only logical thinking.So do some research about the companies before taking interviews.Always look for job description.



Like BigBoss Kanja Karupu some students ask me what is attitude mam? Companies does not look only for your tech skills.Most of the time you have to work in a team.So interviewer will check whether you will get aligned with their company’s work culture.A new entry may spoil an entire team because of his attitude.Some students believe that they already learnt everything ,this attitude will stop him/her from learning from others.He will try to overshadow others. attitude

I have listed only few of the reasons.Will it be interesting to hear more from the person who has taken 100’s of interviews.To know more ,register for the Interview Cracking Skills workshop by Guvi

To Book your tickets click here Register

Get the best Interview tips from the Industry expert Mr.Arun Prakash (Founder/CTO of GUVI) -Technologist with 15+ years of working experience in companies like Honeywell,KLA Tencor,Kalido,Paypal, Symantec and Guvi

Why to attend?

You will get the answer for:

  1. How to get your first job?
  2. Finding your dream company?
  3. How to build your Tech confidence?
  4. Behavior advice, resume preparation, technical preparation?
  5. Top 10 mistakes students make in interview.
  6. Short cuts to crack interview.
  7. How to prepare your job role? (Service Vs Product companies)
  8. Experience sharing
  9. How to overcome communication barriers?


Mr.Arun Prakash (Founder/CTO of GUVI) with 15+ years of experience in product companies, AI & ML expert.

Fees 799/- per head.,10% Group discount(Minimum 4 in a group)

To Book your tickets click here Register

For tech courses click GUVI

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Celebrate the Big Data Problems – #3

How to have our basic statistics (Mean, Median, SD, Var, Cor, Cov) computed using R language?

The dataottam team has come up with blog sharing initiative called “Celebrate the Big Data Problems”. In this series of blogs we will share our big data problems using CPS (Context, Problem, Solutions) Framework.


In statistics Mean, Median, Standard Deviations, Variance, Correlation, or Covariance are foundations steps. From Data Analyst to Data Scientist they will use the basic statistics. It can be arrived using many languages. But here we will use the language called R.

Mean – The mean is the average of the numbers. And it’s easy to calculate; add up all the numbers, then divide by how many numbers there are. In another words it is the sum divided by the count.

Median – The median is the middle of a sorted list of numbers. To find the median, place the numbers in value order and find the middle.

Standard Deviation – SD is a measure of how spreads out numbers are. And the symbol for SD is sigma, a greek letter.

Variance – The Variance is a measure of how spread out numbers are and it is the average of the squared difrences from mean.

Correlation- The Corereltion is when two sets of data are strongly linked together we say they have a high correlation. Correlation is positive when the values increase together, and it is negative when one value decreases as the other increases.

Covariance – covariance is a measure of how much two random variables change together.


How to have our basic statistics Mean, Median, Standard Deviation, Variance, Correlation, and Covariance are computed using R language.


Use the below functions as applies with assumptions of x and y are vectors.

  • mean(x) median(x) sd(x) var(x) cor(x,y) cov(x,y)

Continue Reading …

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Celebrate the Big Data Problems – #2

Celebrate the Big Data Problems – #2

How to identify the no of buckets for a Hive table while executing the HiveQL DDLs ?

The dataottam team has come up with blog sharing initiative called “Celebrate the Big Data Problems”. In this series of blogs we will share our big data problems using CPS (Context, Problem, Solutions) Framework.


Bucketing is another technique for decomposing data sets into more manageable parts. For example, suppose a table using the date as the top-level partition and the employee_id as the second-level partition leads to too many small partitions. Instead, if we bucket the employee table and use employee_id as the bucketing column, the value of this column will be hashed by a user-defined number into buckets. Records with the same employee_id will always be stored in the same bucket. But the challenges are to identify the no of buckets for certain Hive tables in the big data system. While creating table you can specify like CLUSTERED BY (employee_id) INTO XX BUCKETS; where XX is the number of buckets. Bucketing has several advantages. The number of buckets is fixed so it does not fluctuate with data. If two tables are bucketed by employee_id, Hive can create a logically correct sampling. Bucketing also aids in doing efficient map-side joins etc.


How to identify the no of buckets for a Hive table while executing the HiveQL DDLs ?


To identify the buckets we need to do a small exercise as below steps,

We need to get the daily / run-wise records from the business, vertical, or domains.
Convert into average percentage of increment by taking at-least five days’ data, or a week data.
Multiple the incremental percenateg with 1024 to have it in incremental size in megabytes
Divide it by 192 or 128 for RCFile and HiveIO respectively
Formulae :
Incremental Records = Total Records / Incremental Records
Incremental Records % of Total = (Incremental Records / Total Records) * 100
Incremental Size in MB = Incremental Records % of Total * 1024
of Buckets = Incremental size in MB / 192 for RCFile
of Buckets = Incremental size in MB / 128 for HiveIO
Reason for conversion in to MB is that Hadoop has it’s file storage blocks in to MB for large blocking.
Example :
If we have initially 100 Records and average increment with 5 Records per run/day wise and we are interested in using RCFile
Incremental Records = 100 / 5 = 20
Incremental Records % of Total = (20 /100 ) * 100 = 20%
Incremental Size in MB = 20 * 1024 = 20480

Continue Reading …

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100+ Interview questions for Software Developer (SDE) / Software Developer In Test (SDET)

SDE/SDET Interview questions that will ramp-up your interview preparation

Myself, Balaji Boggaram Ramanarayan – I bag experience in taking/preparing for interviews in several big companies and always felt sharing a few of them such that it might be useful for you in interview preparation.

Note : These questions might help you ramp-up your speed in path of preparing to SDE /SDET interviews in most techie companies. 

 SDE – Software Development Engineer
 SDET – Software Development Engineer in Test 

All that you need is how well can you stand out in your interviews.
SDE and SDET Interview Questions


  1. Heap – Max Heaps and Min Heaps
  2. Conversions : Decimal ,Binary, Hex, Octal (All other possible combinations)
  3. 90 Degrees Matrix conversion
  4. Quick Sort + Applications
  5. Merge Sort + Applications
  6. Remove duplicates in a String — In place
  7. Reverse a string – Inplace
  8. Decide if 2 strings are anagrams or not ?
  9. Binary Search
  10. Reverse SLL without using any extra nodes
  11. Maximum Sub array [Kadane Algorithm]
  12. Find an element which is repeated more than n/2 times in a given set/array. [Moores Voting algorithm]
  13. Find and element in rotated Binary sorted array
  14. Implement power function without pow() function
  15.  Verify if given linked list is circular/cyclic or Acyclic. Follow up can be to indicate the starting point of cycle
  16. Implement Blocking queue
  17. Find a pair in array that will sum up to particular number
  18. Reverse a double linked list
  19. Reverse pairs in SLL. i.e I/P : a->b->c->d->e->f O/p : b->a->d->c->f->e
  20. Segregate even and odd nodes in a given linked list
  21. Addition of 2 linked lists to separate one. (also learn inplace)
  22. Convert SLL in to DLL (XOR based linked lists)
  23. Circular shift an array of integer input array by ‘k’ number of elements
  24. Search for a given pattern in text [Rabin Karp Algorithm]
  25. atio() and itoa() implementations (ASCII to integer and Integer to ASCII)
  26.  Binary Semaphores
  27. Generate subsets of given set of integers
  28. Generate all permutations of a given string
  29. Level order Traversal
  30. Inorder successor of a given node in BST (Binary Search Tree)
  31. Find ‘k’ largest /smallest elements in a given array (Hint : can use heaps)
  32. Heap Sort + applications
  33. Find minimum length unsorted sub array on which storing them makes complete sorted array
  34. Search if a given pattern exists in input text using Suffix Arrays
  35. Re-arrange a string so that all same characters are ‘d’ distant apart
  36. Knights tour problem
  37. Rat in Maze [Back tracking]
  38. Find out if two rectangles overlap or not
  39. Find closest pair of points in the given plane
  40. Find all subset of elements in the given set whose sum equals to a given target
  41. Compute x^y such that it can work for floats and negative values
  42. Find median of  given two input sorted arrays
  43. Find total no of zeros in a given array of 1’s followed by 0’s
  44. Find if there is any sub array which sums up to zero
  45. Count number of inversions in a given array
  46. Find minimum element in a rotated sorted array
  47. Find the fixed point in the given array
  48. Find the maximum sub array sum [D&C]
  49. Count # of occurrences of a number in the sorted array
  50. Find the max and min element in a given array with minimal number of comparisons
  51. Check if a number is multiple of 3 or not ?
  52. One line function to check if a number is power of 2 or not ?
  53. Function to multiple a number by 7.
  54. Function to multiple two numbers without using * product operator
  55. Function to write Fibonacci series in iterative manner
  56. Generate all prime numbers less than or equal to n [Sieve of Erastho..]
  57. Given a number, Find the next biggest palindrome number
  58. Implement logic for fair coin from biased coin
  59.  Check if a number is divisible by 7 without mod operator
  60. Find all the possible words from a phone keypad
  61. Lexicographic sort of permutation of all words
  62. Shuffle a given array / deck of cards [Fisher Yates Algo]
  63. Reservoir Sampling Algorithm
  64. Select ‘k’ random elements from ‘n’ elements
  65. Given a number ‘n’. generate a pascal triangle out of it.
  66. Write an exponential precision function [Taylor series]
  67. Generate all prime factors of a given number
  68. Generate all possible combination of ‘r’ elements in a given array of size ‘n’ [Probability Distribution Function]
  69. Length of Longest common sub sequence of given sequence of numbers
  70. Find minimum cost path in a given cost matrix
  71. Total # of solutions in a coin change problem
  72. Find binomial co-efficient
  73. Knap-sack standard problem
  74. Egg-Drop standard problem
  75. Length of longest palindrome sequence
  76. Palindrome Partitioning
  77. Maximum Length of chained increasing pair
  78. Find the middle of given linked list
  79. Check if a given Single linked list is a palindrome or not
  80. Insert/Delete/Search in max heap
  81. Implement sizeof() operator
  82. Find successor of given BST
  83. Find all triangle triples in given array
  84. Find lowest common ancestor of a given node
  85. Return a single element by knocking out all other elements by ‘k’ [Josephus]
  86. Given a sorted skewed binary tree, Create a BST out of it.
  87. Given an array with integers, Output all the elements which were repeated exactly twice
  88. Maximum depth/height/diameter of a given tree
  89. Serialize and De serialize a given binary tree
  90. Find single repeated or non-repeated number in conditional list. (XOR)
  91. Implement “diff” in linux
  92. Program to count # of set bits in a given integer.
  93. Convert BST to doubly linked list
  94. Convert integer to String without .toString()
  95. GCD of two numerals
  96. Given an array in post order traversal, check whether the given array is in BST or not
  97. Reverse the words in a given English sentence
  98. Get the median of a stream of large numbers
  99. Print all the paths of a given Binary Tree from root to leaf
  100. Modify array such that arr[i] == arr[arr[i]] Inplace
  101. Find the missing number in a billion number list
  102. Bit wise addition

Watch interesting videos for Data Structures and Algorithms & C, C++, JAVA in your native language (Tamil, Telugu, Hindi) here.

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ட்விட்டரின் ட்விஸ்ட்ஸ்..

ட்விட்டர் பற்றிய ஒரு இன்ட்ரொ. உங்களுக்கு பேங்க்ல அக்கௌன்ட் இல்லையென்றாலும் பரவாயில்லை. ஆனால்; ட்விட்டர், ஃபேஸ்புக்ல அக்கௌன்ட் இல்லையென்றால் ஒரு தீவிரவாதியாயைப்போல் பார்க்கிறார்கள். ஆகையால் வாருங்கள் உங்களை ஒரு நல்ல பிரஜையாக மாற்றுகிறேன்.

   ட்விட்டரில் அக்கௌன்ட் எப்படி தொடங்குவது என்று பார்ப்போம். அடுப்பில் சுடுத்தண்ணீர் காய்ச்சுவதுப்போல் சுலபமான ஒன்றுதான். என்று அட்ரஸ் பாரில் டைப் செய்யவும். உடனே திரை வந்துவிடாது எனில் நமது நெட் ஸ்பீட் அப்படி. சற்று நேரம் பொறுத்து விரியும்.

        New to twitter? என்ற தலைப்பில் Sign up for twitter என்ற பட்டனை க்ளிக் செய்யவும். தொடர்ச்சியாய்  Join Twitter Today என்று பேஜ் ஒப்பன் ஆகும். அதில் Full name என்ற இடத்தில் உங்களின் உண்மையான பெயரை தருவதும் மாற்றி வைத்து தொடங்குவதும் உங்கள் விருப்பம். ட்விட்டரில் உள்ள வசதி என்னவென்றால் உங்களின் “Personal Identity” எதுவும் தேவையில்லை என்பதே.

         அடுத்து E-mail address கொடுக்கவும். அப்புறம் வழக்கமாக காதலன்(கள்) /காதலி(கள்) பெயர் அதாவது பாஸ்வோர்ட். இறுதியாக Username அடுத்தவரை கவரும் வண்ணமாக முட்டாள், முசுடு, என்று எதை வேண்டுமானாலும் வைத்துக்கொள்ளலாம். இல்லையென்றால் அடுத்தவர்கள் எப்படியும் அழைக்கபோதில்லை என்று அறிவாளி என்றுக்கூட வைத்துகொள்ளலாம்.

        ஒருவழியாக முடித்தபின் Create my account என்ற  பட்டனை பிரஸ் செய்யவும். அதன்பின் ப்ரோபைல் டிசைனில் மானே, தேனே, பொன் மானேன்னு போட்டுக்கோங்க.இனிமே உங்க வாய்தாவை தொடங்கலாம்.

    நீங்கள் யாரென்று தெரியாமல் ஆனால், உங்கள் எண்ணங்களையும், கருத்துகளையும் மட்டுமே தெரியபடுத்தலாம் “படுத்தி எடுக்கலாம்”.  கொஞ்சம் நேரம் இளையராஜா பாடல்கள் கேட்டு ரிலாக்ஸ் செய்வதுப்போல். ப்ரீயா எதையவாது பேசிவிட்டு போகலாம். அதற்கென்று  அதிகமாகவும் பேச முடியாது 140 கேரக்டர்ஸ்ல முடிச்சிடனும் கண்டிஷன்ஸ் அப்பளை ஆகாத ஒரே விஷயம் மரணம் மட்டும்தான். 140 கேரக்டர்ஸ்ல முடிக்க வேண்டும் என்பதால் நன்றாக எழுதுபவர்களுக்கு சிந்தனையை தூண்டும். நிறைய எழுத்தார்வம் மிக்கவர்களுக்கு  நல்ல குலுக்கோஸ்.

    வெட்டியாக பொழுதை கழிக்க விரும்புபவர்களுக்கு இது ஒரு வேஸ்ட் பேப்பர் என்ன வேண்டுமானாலும் கிறுக்கிவிட்டு போகலாம். ஆனால் அதற்கான எதிர்வினை வந்தால் சந்தித்துதான் ஆகவேண்டும். ஏனேன்றால் இது சோஷியல் மீடியா. நீங்கள் தொடர்புக்கொள்ள முடியாத பிரபலங்களை ஃபாலோ செய்து அவர்களுடன் உரையாடலாம். உங்களின் ஃ ஃபாலோவ்வர்ஸ் அதிகம் ஆக ஆக நீங்களும் பிரபலம்தான். நீங்களும் பிராப்ளம் ஆக சாரி பிரபலம் ஆக  என் வாழ்த்துக்கள்!.

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Its not BANG BANG BANG , its PAN PAN PAN ! ! !


Hi Friends this is praga, In this post ,I want to share a information about PAN Account Number, It sounds crazy but I got amused after hearing this and i hope you too will be.

Most of us have PAN Card, It is issued by income Tax Department, it is used for bank deposits above Rs. 50,000/=, purchase and sale of immovable properties, vehicles etc.

It is a 10 character alphanumeric identifier. Each char says something about them, lets listen what they are going to say..:-p

Continue reading Its not BANG BANG BANG , its PAN PAN PAN ! ! !

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Double Dhamaka using 3.5mm Stereo Splitter

Usually in many situations, we would have tried to listen to our favorite song with our friends or loved one’s using single Head phone, which will not give full comfort in listening to that song easily. Is there is a Solution for this?


Yeah, here is a solution :-). We do have 3.5mm stereo splitter which looks something like this,

splitter basic
3.5 mm Stereo Splitter

3.5 stereo splitter will connect two pairs of head phones to one output(Device like mobile, Laptop etc.,). Thus we can use two earphones connected to one output at the same time and listens to the songs with our buddies  🙂

How it can be used?

We should insert the male pin to your device’s 3.5mm jack and your headphone to the two pin holes of splitter.

Stereo Splitter Connected to Device
Ear Phones Connected to Splitter

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