Unthinkable Solutions Full Stack Developer Interview Questions and Answers

Round duration - 40 minutes
Round difficulty - Easy

Q1. 
Find a Node in Linked List
Given a singly linked list of integers, your task is to implement a function that returns the index/position of an integer value 'N' if it exists in the linked list. Return -1 i...read more
Ans. 
Implement a function to find the index of a given integer in a singly linked list.
• Traverse the linked list while keeping track of the index of each element.

• Compare each element with the target integer 'N'.

• Return the index if 'N' is found, otherwise return -1.

• Handle cases where the list is empty or 'N' is not found.

• Consider the constraints on the number of test cases and the length of the linked list.
Answered by AI
Add your answer
Q2. 
Implement Stack with Linked List
Your task is to implement a Stack data structure using a Singly Linked List.
Explanation:
Create a class named Stack which supports the following operations, each in O(1...read more
Ans. 
Implement a Stack data structure using a Singly Linked List with operations in O(1) time.
• Create a class named Stack with getSize, isEmpty, push, pop, and getTop methods.

• Use a Singly Linked List to store the elements of the stack.

• Ensure each operation runs in constant time complexity (O(1)).

• Handle edge cases like empty stack appropriately.

• Example: For input '5', '3 10', '5', '1', '2', '4', the output should be '10', '1'
Answered by AI
Add your answer
Q3. 
Cycle Detection in a Singly Linked List
Determine if a given singly linked list of integers forms a cycle or not.
A cycle in a linked list occurs when a node's next points back to a previous node in the ...read more
Ans. 
Detect if a singly linked list has a cycle using O(N) time complexity and O(1) space complexity.
• Use Floyd's Tortoise and Hare algorithm to detect cycle in linked list

• Maintain two pointers, slow and fast, moving at different speeds

• If there is a cycle, the two pointers will eventually meet

• If one of the pointers reaches the end of the list (null), there is no cycle
Answered by AI
Add your answer

Round duration - 20 minutes
Round difficulty - Easy

Q1. 
Top View of Binary Tree
Given a binary tree of integers, the task is to return the top view of the given binary tree. The top view of the binary tree is the set of nodes visible when viewed from the top.
...read more
Ans. 
Return the top view of a binary tree given in level-order format.
• Traverse the binary tree in level-order and keep track of the horizontal distance of each node from the root.

• Use a map to store the nodes at each horizontal distance, and only keep the first node encountered at each distance.

• Return the values of the nodes stored in the map in sorted order of their horizontal distance.

• Example: For the given binary tree, th
Answered by AI
Add your answer
Q2. 
Problem Statement: Delete Node In A Linked List
Given a singly linked list of integers and a reference to a node, your task is to delete that specific node from the linked list. Each node in the linked li...read more
Ans. 
Given a singly linked list of integers and a reference to a node, delete the specified node from the linked list.
• Traverse the linked list to find the node to be deleted

• Update the pointers to skip over the node to be deleted

• Print the modified linked list after deletion
Answered by AI
Add your answer

Create a CRUD application

Q1. Javascript, hoisting ,promise ,callback function
Add your answer
Q2. Array , object ,JSON,for loop
Add your answer
Q3. Introduction react js,and other frameworks ,like angular, Vue
Add your answer

Q1. What are your salary expectations?
Add your answer
Q2. Basic details for joining company
Add your answer

Q1. Basics questions of react native
Add your answer

Very basic aptitude questions along with few coding questions

Q1. A problem statement was given and we had to provide an optimal approach to design and handle that problem
Add your answer
Q2. Oops concepts, SQL queries
Add your answer

The basic question is related to profit percentage, time and distance

Q1. Is the database schema of any type?
Ans. 
Yes, the database schema can be of various types such as relational, hierarchical, network, object-oriented, etc.
• Relational database schema is the most common type, using tables to store data with relationships between them.

• Hierarchical database schema organizes data in a tree-like structure.

• Network database schema allows multiple relationships between records.

• Object-oriented database schema stores data as objects with...read more
Answered by AI
Add your answer

BASIC DSA LIKE ARRAY AND STRING

Q1. System Design for Electric Charger app ?
Ans. 
System design for an electric charger app involves creating a user-friendly interface, integrating with payment systems, and ensuring efficient charging station management.
• Design a user-friendly interface for users to locate and reserve charging stations

• Integrate with payment systems for seamless transactions

• Implement efficient charging station management to monitor availability and maintenance

• Consider scalability for ...read more
Answered by AI
Add your answer
Q2. Design digram for that ?
Ans. 
Design diagram for a software developer role.
• Use UML diagrams to show class relationships and interactions

• Include components like classes, interfaces, relationships, and methods

• Consider using tools like Lucidchart or draw.io for creating the diagram
Answered by AI
Add your answer

There was aptitude test in the first round, They were mainly quantitative, English questions..
And we had coding questions (3 questions) and they were medium questions..

Q1. We had given a problem statement, and we had to write down the solution (technical solution) and it was pen and paper based..
Add your answer
Q2. Emergency traffic signal system, in case of ambulance
Add your answer

Q1. They asked mainly based on the system design which we had written and about our projects etc...
Add your answer