Vistaar Technologies Interview Questions and Answers

Train questions, quant, reasoning

Q1. What is binary search puzzle
Ans. 
Binary search is a search algorithm that finds the position of a target value within a sorted array.
• Divide the array in half and compare the target value with the middle element

• If the target value is smaller, search the left half of the array. If larger, search the right half

• Repeat the process until the target value is found or the subarray is empty
Answered by AI
Add your answer
Q2. What is hashMap
Ans. 
HashMap is a data structure in Java that stores key-value pairs and allows for fast retrieval of values based on keys.
• HashMap is part of the Java Collections framework.

• It uses hashing to store and retrieve elements quickly.

• Each key in a HashMap must be unique.

• Example: HashMap<String, Integer> map = new HashMap<>(); map.put("apple", 5); int value = map.get("apple");
Answered by AI
Add your answer
Q3. Dbms queries views joins
Add your answer

Q1. Puzzle data structure
Add your answer
Q2. Pattern problem
Add your answer
Q3. OS threads, Software development lifecycle
Add your answer

Q1. Normal hr questions
Add your answer
Q2. Tell me about yourself
Add your answer
Q3. About family, home location, where do u stary
Add your answer

Basic quantitative questions along with DSA and coding questions were asked

Q1. Explain Greedy algorithms and Divide and Conquer techniques
Ans. 
Greedy algorithms make the optimal choice at each step, while Divide and Conquer breaks a problem into smaller subproblems.
• Greedy algorithms select the best option at each step without considering the overall solution

• Divide and Conquer divides a problem into smaller subproblems, solves them recursively, and then combines the solutions

• Example of Greedy algorithm: Dijkstra's shortest path algorithm

• Example of Divide and C...read more
Answered by AI
Add your answer
Q2. Explain Joins, types of joins
Ans. 
Joins are used to combine rows from two or more tables based on a related column between them.
• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table.

• FULL ...read more
Answered by AI
Add your answer
Q3. Explain Multithreading
Ans. 
Multithreading is the ability of a CPU to execute multiple threads concurrently, allowing for improved performance and responsiveness in software applications.
• Multithreading allows multiple threads to run concurrently within a single process.

• Each thread has its own stack and program counter, but shares the same memory space.

• Multithreading can improve performance by utilizing multiple CPU cores efficiently.

• Examples of m...read more
Answered by AI
Add your answer
Q4. Explain deadlocks
Ans. 
Deadlocks occur when two or more processes are unable to proceed because each is waiting for the other to release a resource.
• Deadlocks happen when processes compete for resources and each holds a resource needed by the other.

• Four conditions must hold for a deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait.

• Examples of resources that can lead to deadlocks include locks, semaphores, and ...read more
Answered by AI
Add your answer
Q5. Explain Binary search algorithm
Ans. 
Binary search is a divide and conquer algorithm that searches for a target value within a sorted array.
• Divide the array in half and compare the target value with the middle element

• If the target value is less than the middle element, search the left half of the array

• If the target value is greater than the middle element, search the right half of the array

• Repeat the process until the target value is found or the subarray...read more
Answered by AI
Add your answer

Aptitude, Logical, Data Structures, Coding

Q1. Tell me abt the projects that you have developed during academics?
Ans. 
I have developed multiple projects during my academics including a web-based student management system and a mobile app for tracking daily expenses.
• Web-based student management system: Developed using HTML, CSS, JavaScript, PHP, and MySQL. Allowed users to register, login, and manage their academic information.

• Mobile app for tracking daily expenses: Built using React Native. Users could input their daily expenses and v...read more
Answered by AI
Add your answer
Q2. Difference between delete, truncate and drop in SQL?
Ans. 
Delete removes specific rows, truncate removes all rows, drop removes entire table structure.
• Delete is a DML command used to remove specific rows from a table.

• Truncate is a DDL command used to remove all rows from a table.

• Drop is a DDL command used to remove the entire table structure.

• Delete can be rolled back, truncate cannot be rolled back, drop cannot be rolled back.
Answered by AI
Add your answer

Logical
Quantitative
Mcq on Dsa like
1.height of binary tree
Question to code on paper 3 code out of which 2 were compulsory to attend
1.string and a rotated string is equal
2.rearrange array like even number first then odd numbers
And so on

Q1. 1. Prepare array String well for this round easy question are expected to code 2. Prepare the most asked puzzle gfg 100 puzzle 2 were asked during the interview 3. Sql queries you have to write and show ...read more
Add your answer