Zenon Interview Questions and Answers

Questions were based on DSA , Databases and SQL

Library System Problem

Offline test of 3 sections, 1st aptitude, 2nd coding and 3rd dbms

Q1. 2 technical rounds. Question were about trees, sql, oops etc
Add your answer
Q2. Buid a binary tree
Ans. 
A binary tree is a data structure where each node has at most two children.
• Start by creating a Node class with left and right child pointers.

• Implement methods to insert nodes, search for a specific value, and traverse the tree (inorder, preorder, postorder).

• Consider edge cases like inserting duplicate values or handling empty trees.
Answered by AI
Add your answer
Q3. Save bst to disk
Ans. 
To save a binary search tree (BST) to disk, you can serialize the tree and write it to a file.
• Serialize the BST using pre-order, in-order, or post-order traversal

• Write the serialized data to a file on disk

• When reading the data back, deserialize it to reconstruct the BST
Answered by AI
Add your answer
Q4. Sql queries, specially joins
Add your answer
Q5. Infinite stream of numbers, store 10 maximum number. (Heap)
Ans. 
Use a max heap to store the 10 maximum numbers from an infinite stream of numbers.
• Implement a max heap data structure to keep track of the 10 maximum numbers.

• As new numbers come in from the infinite stream, compare them with the root of the heap.

• If the new number is greater than the root, replace the root with the new number and heapify.

• Keep the heap size limited to 10 to store only the 10 maximum numbers.
Answered by AI
Add your answer

Q1. Write sql query
Ans. 
Write a SQL query
• Understand the requirements of the query

• Identify the tables and columns needed

• Use appropriate joins and conditions

• Test the query before executing
Answered by AI
Add your answer
Q2. Write java 8 code
Ans. 
Write Java 8 code to demonstrate array manipulation
• Use Stream API for array manipulation

• Use lambda expressions for concise code

• Use method references for cleaner code
Answered by AI
Add your answer

Q1. How pandas groupby works internally?
Ans. 
Pandas groupby function in Python is used to split data into groups based on some criteria and then apply a function to each group.
• Groupby function splits the data into groups based on the specified criteria

• It then applies a function to each group separately

• The result is a new object with the function applied to each group
Answered by AI
Add your answer
Q2. Difference between Linear and tree models
Ans. 
Linear models assume a linear relationship between variables, while tree models use a hierarchical structure of decisions.
• Linear models assume a linear relationship between input variables and output, while tree models can capture non-linear relationships.

• Linear models are simpler and easier to interpret, while tree models can handle complex interactions between variables.

• Linear models are prone to overfitting with hig...read more
Answered by AI
Add your answer

Q1. How soon can you join
Ans. 
I can join within two weeks of receiving an offer.
• I can start within two weeks of receiving an offer

• My current notice period is two weeks

• I am available to start immediately
Answered by AI
Add your answer