Graduate Engineer Trainee

It was a simple round just an introduction and asked some data structure-related questions, and DBMS also 
it was morning time and I get a slot from 11 am to 11.30 
1. What is a list 
2 . What is a pointer 
3. Does java use a pointer 
4. What are SQL and NoSQL
5. What you know about reliance jio
6. What is the OOPS concept
7. DBMS concept ( primary key, 2 vs 3 tier architecture, ACID properties )
8. The logic for basic loops Is there any way to print 1 to 100 without using any loops Also the interviewer started to defend their side and refuse your answer to check whether your confidence will break or not
9. What are joins? Types of joins?

Given a binary tree, convert this binary tree into its mirror tree.

A binary tree is a tree in which each parent node has at most two children.

Mirror of a Tree: Mirror of a Binary Tree T is another Binary Tree M(T) with left and right children of all non-leaf nodes interchanged.

Note:

1. Make in-place changes, that is, modify the nodes given a binary tree to get the required mirror tree.

You have been given a matrix of ‘N’ rows and ‘M’ columns filled up with integers. Find the minimum sum that can be obtained from a path which starts from the top left corner and ends with the bottom right corner.

From any cell in a row, we can move to the right, down or the down-right diagonal cell. So from a particular cell (row, col), we can move to the following three cells:

Down: (row+1,col)
Right: (row, col+1)
Down right diagonal: (row+1, col+1)

You have been given an integer 'N'.

Your task is to return true if it is a power of two. Otherwise, return false.

An integer 'N' is a power of two, if it can be expressed as 2 ^ 'K' where 'K' is an integer.

For example:

'N' = 4,
4 can be represented as 2^2. So, 4 is the power of two, and hence true is our answer.

1. Introduce yourself 
2. What is your role in the company 
3. Which language do you prefer python java 
4 what is memory management in java 
5 what is memory management in python 
6 How garbage collector works in java 
7 what is a cache 
9 What are AI and cloud computing do you have any experience 
10 print power of a given number without using multiple symbols in java 
11 write SQL query to show 2nd topper of the class 
12 what is a group by 
13 Differences between truncate delete remove 
14 Show polymorphism in java by writing code 
15 real-life examples of Inheritance 

HR Question
16 What you know about jio 
17 Are you willing to reallocate
18 why do you want to leave this company

You are given an integer 'N'. For a given 'N' x 'N' chessboard, find a way to place 'N' queens such that no queen can attack any other queen on the chessboard.

A queen can be killed when it lies in the same row, or same column, or the same diagonal of any of the other queens. You have to print all such configurations.

Given a list of cities numbered from 0 to N-1 and a matrix 'DISTANCE' consisting of 'N' rows and 'N' columns denoting the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the starting city?

The interview started with basic questions 
1. Introduction 
2 Tell me about your internship 
3 What stream API in java
4. Interface in java.
5. Is multiple inheritances possible, why is possible in c++ no in java
6. What is hibernate (Internship related question)
7. What is PostgreSQL
8 . Best sorting algorithm 
9 Tell about merge sort 
10 why merge sort better than quick sort
11 ask about n queen problem and traveling salesman problem then ask to write code

HR
the same person as 1st interview so does not ask me anything