Apti + Technical Test: There were around 4 sections, all the sections were further divided into few subsections.
- Apti: Quantitative, logical reasoning, Flowchart questions.
- Coding skills: C++ output questions,
- Computer Science knowledge: Data Structures insertion, deletion related questions, many questions from AVL Trees, BSTs, stack and queue operations related questions, etc, covered a lot of topics from DBMS (B+ trees, normalization forms, BCNF and all), OS, OOPs,
The questions in the test were from a very wide range of topics. This test was on oracle’s own platform. Around, 70 students got shortlisted for the interviews. There were 3 Technical rounds and 1 HR round for all, but they took 4th Technical interview of few candidates along with me.
1st Technical Interview:
- Write code for Nibble swap (Bit Manipulation).
- Reversal of Linked List.
- Program to implement runtime polymorphism (virtual function).
I was able to write and explain each and every code properly. Please note that they want a very well written proper code. (It took around 25 mins)
2nd Technical Interview: This round was to check knowledge for core subjects and Project-related questions were asked. Few questions which I remember are:
- All almost every topic related to OOPs
- The basic definition of OOPs.
- Define and give some real-life examples of Encapsulation, Inheritance, Polymorphism, data Abstraction, types of polymorphism. (He wanted to check basics and I explained him all)
- Then, he asked to write code for different types of inheritance.
- What is a friend function and write code to implement it?
- Now, DBMS.
- What is normalization and why we need to perform that?
- The basic difference in all types of normalization forms (2NF, 3NF, BCNF).
- Types of Joins.
- Then he asked me how many OS you have worked on. I told him Linux (Ubuntu) and Windows. So he asked me what is the difference between both of them and which of them is better for development and why? My answer was not satisfactory for him but this didn’t affect much. You have to be mentally prepared for this kind of question too.
- Some basic Project related queries like how you implemented a few functions.
- At last, he gave me a very common puzzle: Measuring 6L water from 4L and 9L buckets
This interview was an explanation kind of and I answered quickly. (Around 30 – 45 mins)
PS: Always take some time to solve the puzzle even if you know it.
3rd Technical Interview: This round was to check DS. They asked some basic questions from Tree, Linked List, Arrays, etc.
- Binary Tree Path Sum.
- Boundary Order Traversal
- Lowest Common Ancestor (LCA).
- Detect and remove Loop in a linked list.
- Stock buy and sell. (started from naive approach and optimized it)
- Implement a queue using stack and Implement stack using queue and optimize the push and pop of both.
These questions were very basic, and they did analyze the code by going through some test cases (dry run). Also, a very detailed discussion on Time and Space complexities. Probably the longest interview. (45 mins)
4th Technical Interview: Started asking about the Internship Project. Based on that he asked me to design an airline scheduling system in which Arrival and Departure Times are given and with some conditions that there can’t be more than n flights at a given time on the run-way. I told him correct logic but he wanted me to write proper code using classes and objects. I tried and somehow wrote the code but he wasn’t that much satisfied. The interviewer was Very supportive so he helped me and suggested a few changes.
Then he asked me some puzzles
- 25 horses puzzle.
- Hour-glass puzzle.
- Then, he asked me some queries.
- Nth Highest Salary
- Some join related query
- Tell me about yourself.
- How was your interview experience so far?
- Asked for my internship at RIL.
- Why do you want to join oracle?
9 students out of 70 made it till the HR round out of which 8 got selected including me, so communication also played a small role overall.
- Thoroughly go through interview experiences as much as you can.
- Practice some basic questions of Linked List and Binary Trees (most imp) and other DS like an array, queue, stack, strings.
- Good knowledge of core subjects like OOPs and DBMS is a must.
- Learn to write SQL Queries.
- Solve and practice puzzles from GFG.
- E-R diagram and Schemas especially if your project has Database related operations.
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