 Written round:
3 hours of written test.
First technical and then aptitude.Few technical questions that I can remember.

int* a = (int*)60; int* b = (int*)40; printf("%d", ab); Print the output. (Ans: 5)
 Given a boolean number in string form. WAP to output the 2’s complement of the number in the same form(string).
 Convert a prefix expression to postfix.
 Some assembly program was given, needed to tell what exactly the program was doing.
 Some basic hash related questions.
Aptitude questions are standard and repeated every time.
Can be looked up on the net. 
 Round1: F2F
 Implement nary tree using downright approach.
Traversal both levelorder and inorder.
Asked to code eveything.  What data structure would you use to store a composite linked list?
Composite means that the data value in the individual nodes could vary among the primitive data types.I started with void* and an enum entry to specify the type to help during retrieval.
Then moved to using union. He looked happy with this.  Implement malloc and free.
 Memory layout of a C program.
 What do I like about Adobe Photoshop from the technical point of view?
How would you load and display a 3 GB data file at runtime.
 Implement nary tree using downright approach.
 Round 2: F2F
 Design and implement garbage collector in C.
Many aspects were discussed here.
When to trigger?
Who is responsible?
Which memory to free?  Given an integer number, how would you determine if it is a palindrome.
He wasn’t too impressed with the stack based method.
Wanted in lesser space complexity.So gave solution like this:
rem = num1%10;
num1 = num1/10;
num2 = num2*10 + rem;if the new number created in equal to the original, it is a palindrome.
He wanted me to optimize it further.So started comparing num1 and num2 also, if the number has evendigits, it would return early.
Also, if the number is a multiple of 10, can outrightly say it is not a palindrome.  Given an integer number, find the next higher palindrome number.
 Design and implement garbage collector in C.
 Round 3: F2F
 Code to check if a binary tree follows the below property.
Every node’s data = sum of left subtree + sum of right subtree.  Design a model for implementing sync mechanism for Google drive.
(handling only the client side).
The same file can be accessed and modified by different clients.
Take care of power failure, no internet connection scenarios too.  Given an infinite stream of boolean digits, need to tell at runtime whether the number received so far is a multiple of 3.
Example, first digit received is 1, so the number is 1 > not a multiple of 3.
the second digit received is 0, so the number is 2 > not a multiple of 3.The constraint is that you can only use a 2bit buffer to store.
Ans: always store the remainder to know if it is a multiple of 3.
in the above example,
rem = 1%3 = 1
when 0 comes, new remained = 2*1 + 0 = 2 %3 = 2.and so on.
 Code to check if a binary tree follows the below property.
 Round 4:
 Code for given a sorted but pivoted array, find the ceiling of a given number.
 Discussion on projects.
Volatile keyword.
Discussion on the use of extern and static.  Big endian and little endian architecture.
How to identify if big endian or little endian.
If something has been written on the disk using bigendian architecture and then read using littleendian architecture, how would happen?
 Round 5:
2 questions asked here, I genuinely didn’t know the answer to.
I just tried attempting in all possible ways and analysing the pros and cons. Given a rectangular sheet of paper and a set of very irregular shapes.
I was to cut these shapes out of the paper, in such a way
that ‘there is a good mix’ of all the pieces and the wastage of paper is minimal.
When I say irregular, it can also have a hole in the middle.  Say now, on a touchscreen display, you have those set of irregular pieces.
You touch at a point and swipe it, the corresponding piece should move in that direction. This game is interactive and needs good time complexity.  Given a fairly large number, need to tell whether the number is part of Fibonacci series or not.
You are not allowed to generate all the number in the Fibonacci series.I was not aware of the direct formula to check this at that point.
So tried the matrix multiplication method to calculate the n^{th} Fibonacci number.
I calculated the 1^{st} number, 2^{nd} number, 4^{th} and so on, till the number exceeded the given number.
And then used a binary search to track the answer down.  Was asked if I could improve the performance on the hardware.
I said by calculating all fours member of the matrix parallelly on four cores, if available. He looked satisfied.
 Given a rectangular sheet of paper and a set of very irregular shapes.
Asked to explain the MVC Design Pattern.
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Cheers!