HashStudioz Technologies Java Developer Interview Questions and Answers

Q1. IT WAS MCQ CODING OUTPUT BASED ROUND IN WHICH TOTAL 45 QUESTION
Add your answer

Q1. IT WAS SUBJECTIVE CODING ROUND IN WHICH 1 OUTPUT BASED AND 3 CODING ROUND
Add your answer

IT WAS 3RD CODING ROUND IN WHICH 3 CODING QUESTIONS AND DURATION 75MIN

Round duration - 60 minutes
Round difficulty - Medium

Students who qualified in first round gets link for this round, this round had 4 questions in total, out of which 1 was output based and 3 was DSA based.

Q1. 
Validate Binary Tree Nodes Problem
You are provided with 'N' binary tree nodes labeled from 0 to N-1, where node i has two potential children, recorded in the LEFT_CHILD[i] and RIGHT_CHILD[i] arrays. Dete...read more
Ans. 
The task is to determine if the given binary tree nodes form exactly one valid binary tree.
• Check if there is only one root node (a node with no parent)

• Check if each node has at most one parent

• Check if there are no cycles in the tree

• Check if all nodes are connected and form a single tree
Answered by AI
Add your answer

Round duration - 75 minutes
Round difficulty - Medium

This round was of 70-75 minutes and had 3 coding questions of easy to medium level. There was some restrictions like we cannot use built-in functions in both second and third subjective round.

Q1. 
Balanced Binary Trees Problem Statement
You are provided with an integer 'H'. Your task is to determine and print the maximum number of balanced binary trees possible with height 'H'.
A balanced binary t...read more
Ans. 
The maximum number of balanced binary trees possible with a given height is to be counted and printed.
• A balanced binary tree is one in which the difference between the left and right subtree heights is less than or equal to 1.

• The number of balanced binary trees can be calculated using dynamic programming.

• The number of balanced binary trees with height 'H' can be obtained by summing the product of the number of balanced...read more
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Medium

This was face to face interview round of 60 minutes. It was mostly based on DSA, some questions was also asked related to my projects and DBMS. Interviewer was kind and good.

Q1. 
Wave Array Sorting Problem
Your goal is to sort a given unsorted array ARR such that it forms a wave array.
Explanation:
After sorting, the array should satisfy the wave pattern conditions:
• ARR[0] &...read more
Ans. 
The task is to sort an array in a wave form, where each element is greater than or equal to its adjacent elements.
• Iterate through the array and swap adjacent elements if they do not follow the wave pattern

• Start from the second element and compare it with the previous element, swap if necessary

• Continue this process until the end of the array

• Repeat the process for the remaining elements

• Return the sorted wave array
Answered by AI
Add your answer
Q2. 
Maximum Sum BST Problem Statement
You are presented with a Binary Tree 'root', which may not necessarily be a Binary Search Tree (BST). Your objective is to identify the maximum sum of node values in any ...read more
Ans. 
The task is to find the maximum sum of node values of any subtree that is a Binary Search Tree(BST).
• Traverse the binary tree in a bottom-up manner

• For each node, check if it forms a BST and calculate the sum of its subtree

• Keep track of the maximum sum encountered so far

• Return the maximum sum
Answered by AI
Add your answer

Round duration - 135 minutes
Round difficulty - Hard

This was the final technical round, it was around 2.5 hours long and based on mostly DSA and little bit Projects, DBMS, OS. Josh mainly focus on DSA and on Tree Data Structure in interview.

Q1. 
Pair Sum in BST Problem Statement
Given a Binary Search Tree (BST) and a target value K, determine if there exist two unique elements in the BST such that their sum equals K.
Input:
An integer T, the nu...read more
Ans. 
The task is to check if there exist two unique elements in the given BST such that their sum is equal to the given target 'K'.
• Traverse the BST in-order and store the elements in a sorted array

• Use two pointers, one at the beginning and one at the end of the array

• Check if the sum of the elements at the two pointers is equal to the target 'K'

• If the sum is less than 'K', move the left pointer to the right

• If the sum is grea...read more
Answered by AI
Add your answer
Q2. 
Find Nodes at Distance K in a Binary Tree
Your task is to find all nodes that are exactly a distance K from a given node in an arbitrary binary tree. The distance is defined as the number of edges between ...read more
Ans. 
The task is to find all nodes in a binary tree that are at a distance K from a given node.
• Implement a function that takes the binary tree, target node, and distance K as input.

• Use a depth-first search (DFS) algorithm to traverse the tree and find the nodes at distance K.

• Keep track of the distance from the current node to the target node while traversing.

• When the distance equals K, add the current node to the result lis...read more
Answered by AI
Add your answer

Round duration - 20 minutes
Round difficulty - Easy

This was the simple 20 minutes round

All multiple-choice questions on object-oriented programming and pointers.

Questions related to linked lists and trees.

Three questions, all regarding LinkedIn, focusing on lists and trees.

Basic multiple-choice questions on programming languages.

DSA round 1 , 3 questions on arrays, LL, trees

DSA round 2 : 3 questions on stack and queue, trees, dp

In first round there were two test
1st is the personality test.
2nd is the aptitude test were they asked about 10 aptitude questions and around 40 coding based questions, some of them were mcq and rest were output based.

Contains 4 DSA based questions, 1 question was hard, and other 3 questions were of medium level.

Aptitude test is there in round 1

Coding test is there

Aptitude+CS fundamentals questions were asked

4 questions majorly based on trees and linked list

Again 3 ques 1 was based on trees,another in linked list and 3rd on kadanes algorithm

Q1. Left view of tree
Ans. 
Left view of a tree is the set of nodes visible when the tree is viewed from the left side.
• Traverse the tree in a level order manner

• Keep track of the first node encountered at each level

• Add the first node encountered at each level to the result array
Answered by AI
Add your answer
Q2. Riddle based question
Add your answer
Q3. Detect a loop in linked list
Ans. 
Use Floyd's Tortoise and Hare algorithm to detect a loop in a linked list.
• Initialize two pointers, slow and fast, at the head of the linked list.

• Move slow pointer by one step and fast pointer by two steps.

• If they meet at any point, there is a loop in the linked list.
Answered by AI
Add your answer