# Nvidia Interview | Set 2 (On Campus for R & D Team, Pune)

• Difficulty Level : Hard
• Last Updated : 10 Sep, 2014

## Aptitude Test (60 min):

4 sections, no negative marking but they had sectional cut-off.
Section 1 (C, C++ ):
15 questions.
Mainly questions of type what will be output of following, type of error.(compile time or run time ,etc.) [Do pointers, pointer to functions and OOP concepts in detail]
This section was quite easy.
Section 2 (Operating System):
10 questions.
Questions on deadlock, process scheduling, priority inversion , look-aside buffer memory, etc.
This section wasn’t that easy…..

Section 3 (Data Structures):
8 questions.
DSA questions on sorting, searching , graph traversal (BFS n DFS),Minimum spanning tree (Prim and Kruskal algo), Shortest path(Dijkstra’s algo).
Time complexity related questions and applications of all above mentioned topics. No straight forward questions.
Toughest section of apti.

Section 4 (Quant):
8 questions.
Questions on probability, series , simple logic puzzles.
Easiest section of apti.
No. of people shortlisted after the aptitude test = 20

## Coding Test (2 Questions 30 min)

3 questions were there out of which we had to solve only 2
1. Implement stack (push and pop) operations using linked list.
2. Find the first non-repeating character in a given string in O(n) time complexity.
3. Given co-ordinates of two rectangles find co-ordinates of intersecting rectangle.
No shortlist after this test.

## Interviews:

ROUND 1 (Technical Interview):
Questions:
3. Find whether no. is even or odd…(I gave mod2 solution)
4. Then he asked about machine cycles required registers required ….what exactly happens at os level…….then drawbacks of all these….
5. So asked to give another solution to do same….so I suggested (X &1)….
6. He said still it require 1 extra register…. I gave another solution using shift operator
7. What are sockets, pipes, inter-process communication?
8. What is little endian and big endian?
9. WAP to determine whether your system is little endian or big endian?
10. Convert little endian to big endian in constant time.
11. I asked what does nvidia exactly do in s/w development section?
12. He asked to give my opinion …. I told they take diff OS n optimize them to work more efficiently (in terms of time and memory) with nvidia cards and GPUs.
13. He said your guess is correct….and explained even more.
They shortlisted 7 people from this round.

ROUND 2 (Technical Interview):
Questions:
1. Volatile memory and volatile variables.
2. Function pointers and one program to implement function pointer.
3. Uses of function pointer…(I said to send a function as argument)….he asked more…(I told that I know only one)
4. What is polymorphism? What is virtual function…? How will you implement if I tell you to develop compiler?
I said, I will maintain a static table to store pointers of virtual functions for each class…so it can be accessed by all objects….and my call to virtual function will be converted as…..
p->fun_ptr->fun()….where p is my pointer to object.(He said this is another use of function pointer)
5. What is function template? Do you know what exactly happen when template is executed? If you don’t then tell how will you do that?
6. What happens in recursive function calls? What are the drawbacks?
8. Design data structure to implement multi-threading.
9. Can you find maximum stack memory available using above data structure….I said….can be….and told how I will do that….(pure imagination it was)….he was impressed
10. He was going too deep at OS level….mainly kernel part….how kernel manages all processes?
12. Storage classes in C++….on which part of memory these variables are stored?
13. What is malloc, calloc function?
14. Memory allocation in struct? Why it is like that….why continuous memory is not allocated to struct variables?
It is like that so the variable can be fetched in single machine cycle…else it may require more than one increasing processing time.
15. Implement your own malloc function such that it will allocate memory of 16 bytes and starting address will always be divisible by 16…..was told to write code.
16. What exactly happens as we free up dynamically allocated memory using free()
I told OS allocate the block of memory to some other process.
17. In class of 100 students there are 24 girls and 32 boys….no 3rd gender person…..
I gave him confused look….and asked how it is possible…? He said that is the question…you tell me….and told me to write equation….
I wrote on paper……32 + 24 = 100
I got a spark ….and I said it is possible only if these are the numbers to base 6….
He said,”Yes….you got it.”
18. Asked about my code which I wrote in coding test…..he doubted on that….I proved it works for all test cases….showed him with some test cases.
19. Again a puzzle… On my birthday party he was invited….so he took a rectangular cake for me….but on the way he was so hungry that he ate a rectangular piece of cake…..The cut piece can be of any size and orientation. I was only allowed to make one straight vertical cut so that I and my sister will get same amount of cake. My answer … In general, when a straight cut is made at any angle through the centre of a rectangle, the resulting pieces are always of equal area. So let’s consider our situation. What if we make a straight cut such that it passes through the centre of both the rectangles?

ROUND 3 (HR Interview):
Questions:
1. How was the day?
2. How was apti, coding test, and entire selection procedure?
4. What does your father expect from you?
I answered this in Marathi then translated to English.
5. Asked about future studies…..why I want to work and not want to go for PG.
7. Are you a good cook? Tell me your special items that other love to eat?
9. Asked whether I follow news…..followed by long discussion on elections, Mr. Narendra Modi and his Gujrat.
10. What is your goal? What you want to achieve?
I said to do something technological breakthrough or want an algo on my name….then our discussion moved to NP-complete problems.
The guy didn’t know anything about it….so started explaining him about NP-complete problems.