Oracle Interview Experience | Set 54 (On Campus)

Pre-Interview Round:
Round 1:
4 sections:
*Communication Skills and English
*Software Engineering Aptitude
*Coding Questions
*General Computer Science
Each section has 4/5 sub-sections. And each sub-section had time limits.
Questions are of easy-moderate level. Speed is of utmost importance. One shouldn’t waste time on difficult questions.

Interview Rounds:

Technical Round 1 (45mins):
The interviewer was very polite and started off by making me feel comfortable with questions like “How are you feeling?”, “Had breakfast?”. She began with very simple questions first.

*Given an integer n, print a rhombus like pattern with stars.
E.g.

Input: 4
Output:
   *
  * *
 * * *
* * * *
 * * *
  * *
   *

*Print a given number in words.

Input: 765
Output: Seven Hundred Sixty Five

https://www.geeksforgeeks.org/convert-number-to-words/

*Given a string, format it as following:

Input: Oracle Applications
Output: O.Applications

*Given a linked list and a number k, reverse the list in groups of k nodes.
I was asked to write code for each one of the above.

*Basic concepts about OOPs.
*Example to explain Inheritance.
*Concepts on Destructor
*Camel and bananas Puzzle
*Candle burning puzzle

Technical Round 2(1hr 20mins):
*Concepts on function overloading – I was given erroneous pieces of codes. Asked to find mistake, correct them and explain what kind of error could it cause (compilation/runtime).
*Overriding of Methods
*ACID properties- Explanation with examples
*Runtime polymorphism with codes for virtual function
*Normalization of database
*What are deadlocks? How to avoid them? Handling a situation with semaphores
*Conflict Serializability

*Given an unsorted array filled with 0,1,2 (each having frequency>1), sort them in a single traversal of the array.
*Given a stack (linked-list representation), sort it in O(n) time. (Hint: Take another stack)
*Given a linked list, sort it using any technique. I had used merge-sort. I was asked to explain why not Quicksort. Also I was asked to derive the time complexites for worst and average cases of both.
*Detect and remove loop in a linked list.https://www.geeksforgeeks.org/detect-and-remove-loop-in-a-linked-list/
*Print all possible root to leaf paths of a binary tree.https://www.geeksforgeeks.org/given-a-binary-tree-print-all-root-to-leaf-paths/
*Implement a queue using stacks
*Find the mirror of a binary search tree.
https://www.geeksforgeeks.org/write-an-efficient-c-function-to-convert-a-tree-into-its-mirror-tree/
*Check if a tree is height balanced or not.https://www.geeksforgeeks.org/how-to-determine-if-a-binary-tree-is-balanced/
*Explanation of 0-1 Knapsack Problem with code
*Logic to find minimum number of nodes that would cover all edges of a graph. I was asked if I was comfortable in graphs. I said no, so he said, okay leave you dont need to write the code.
*Puzzle on apples,oranges and mixed fruits
*Puzzle:
1st statement says: Atleast 1 statement is wrong
2nd statement says: Atleast 2 statements are wrong
..
100th statement says: Atleast 100 statements are wrong
How many statements are right?

Technical Round 3(1hr):
*Basic questions on Java
*Advantages of RDBMS over file systems
*Explanation of my summer project at CNeRG
*I had a full stack web development project. I was asked about how I implemented its backend. I had to draw ER Diagrams for the schema. I had to write prototypes of all the functions that I had implemented. Make sure you keep your tables optimally normalized when you show it to them.
*I was asked to design a model of an application whose specifications the interviewer had stated. A layout of the UI and clear diagrams to explain the underlying operations was what was required. I mentioned functionalities to ensure scalability, space-time trade-off, ease pf customer usage and security. He asked me to write an encryption algorithm to store a password in a database. I said I dont know any standard cryptographic algorithm but I wrote code for a very basic encryption, by converting characters to their ASCII values and applying a function over them, and storing the resultant string. He seemed satisfied.
*He asked a few nested queries involving a lot of joins.
*He asked if i have any questions for him. I asked 3 questions regarding their ERP and Cloud services.

Final HR Round (15 mins):
*Tell me about yourself
*With a CGPA of 9, why would you go for a job and not higher studies?
*Why Oracle?
*What is it in your CV which you think is an achievement for you?
*Tell me about your interests
*Are you a leader or a follower?
*Give me 3 adjectives which your best friend would use to describe you.
*If I give full authority of your city for 3 hours, what are the changes you would want to implement and how.
*Location Preference
*Do you have any questions?

Suggestions:
*Do not get nervous, maintain your calm. These are very nice people.
*If the interviewer asks for an O(n) approach and you are unable to think of one, tell him all the O(n^2), O(nlogn) approaches which come to your mind. Let them know that your mind isn’t idle.
*Keep a constant smile on your face, not just in the HR round, but in technical rounds too while convincing them with your solution.
*Be very thorough with atleast one subject apart from Algorithms. Preferably DBMS. Knowledge of Java is an added bonus.
*Be confident, but don’t sound arrogant,
*Keep calm, code and study GeeksfoGeeks. 😛