100+ Software Engineer Trainee Interview Questions and Answers for Freshers

Check if a given singly linked list of integers is a palindrome or not.

• Traverse the linked list to find the middle element using slow and fast pointers.

• Reverse the second half of the linked list.

• Compare the first half with the reversed second half to determine if it is a palindrome.

• Example: Input: 1 -> 2 -> 3 -> 2 -> 1 -> NULL, Output: true

Implement a function to search for a target integer in a 2D matrix with sorted rows.

• Iterate through each row of the matrix and perform a binary search on each row to find the target integer.

• Start the binary search by considering the entire row as a sorted array.

• If the target is found in any row, return 'TRUE'; otherwise, return 'FALSE'.

Calculate total score based on guessing colors in a slot machine.

• Iterate through each slot in the original and guess strings to compare colors.

• Count perfect hits when color matches in correct slot, and pseudo-hits when color matches in different slot.

• Calculate total score by adding perfect hits and pseudo-hits.

• Handle edge cases like invalid input strings or exceeding constraints.

Find the maximum level sum in a binary tree by calculating the sum of nodes at each level.

• Traverse the binary tree level by level and calculate the sum of nodes at each level.

• Keep track of the maximum level sum encountered so far.

• Return the maximum level sum as the final result.

Calculate x raised to the power of n. Handle edge case of 0^0 = 1.

• Accept x and n as input from user

• Compute x^n and display the result

• Handle edge case of 0^0 = 1

• Ensure x is between 0 and 8, n is between 0 and 9

Count the total number of inversions in an integer array.

• Iterate through the array and for each element, check how many elements to its right are smaller than it.

• Use a merge sort based approach to efficiently count the inversions.

• Keep track of the count of inversions while merging the sorted subarrays.

• Example: For input [2, 4, 1, 3, 5], there are 3 inversions: (2, 1), (4, 1), and (4, 3).

Check if a given singly linked list is a palindrome or not.

• Traverse the linked list to find the middle element using slow and fast pointers.

• Reverse the second half of the linked list.

• Compare the first half with the reversed second half to determine if it's a palindrome.

Given an array and a target sum, find pairs of elements that add up to the target sum.

• Iterate through the array and for each element, check if the complement (target sum - current element) exists in a hash set.

• If the complement exists, add the pair to the result list.

• Sort the result list based on the first element of each pair, and then the second element if the first elements are equal.

The N Queens Problem involves finding all possible placements of N queens on an N x N chessboard where no two queens threaten each other.

• Understand the constraints of the problem: N represents the size of the chessboard and the number of queens, and queens can attack each other if they are in the same row, column, or diagonal.

• Implement a backtracking algorithm to explore all possible configurations of queen placements without conflicts.

• Ensure that each valid configuration is ...read more

The question covers topics like two's complement, data structures, machine learning, and OOPs concepts in Java.

• Two's complement of a number 1001 is -0111.

• Data structures are ways of organizing and storing data in a computer so that it can be accessed and used efficiently. Examples include arrays, linked lists, stacks, queues, trees, and graphs.

• Machine learning is a subset of artificial intelligence that involves training algorithms to make predictions or decisions based on da...read more

Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• Abstract class can have method implementations, while interface cannot.

• A class can implement multiple interfaces, but can only inherit from one abstract class.

• Interfaces are used to define contracts for classes to implement, while abstract classes are used to provide a common base for subclasses.

• Example: Abstract class 'Shape' with abstract method 'calculateArea' and...read more

Develop a 'To Do List' application with modern design and functionality like 'Add', 'Edit', 'Delete', and 'View List' within ½ hour.

• Use HTML, CSS, and JavaScript for front-end development

• Implement CRUD operations for tasks (Create, Read, Update, Delete)

• Design a user-friendly interface with header and footer

• Utilize localStorage or backend server for data storage

Hooks are functions that allow us to use state and other React features in functional components.

• useState is a hook that allows us to add state to functional components.

• useRef is a hook that allows us to create a mutable reference that persists across renders.

• useEffect is a hook that allows us to perform side effects in functional components.

• useState example: const [count, setCount] = useState(0);

• useRef example: const inputRef = useRef(null);

• useEffect example: useEffect(() =>...read more

Overloading is having multiple methods in the same class with the same name but different parameters. Overriding is implementing a method in a subclass that is already present in the superclass.

• Overloading involves multiple methods with the same name but different parameters

• Overriding involves implementing a method in a subclass that is already present in the superclass

• Overloading is determined at compile time, while overriding is determined at runtime

I am familiar with JDBC, Servlets, Hibernate, Spring, Apache Tomcat, and build tools like Maven.

• Experience with JDBC for database connectivity in Java applications

• Knowledge of Servlets for handling web requests and responses

• Understanding of Hibernate for object-relational mapping in Java

• Familiarity with Spring framework for building enterprise Java applications

• Experience with Apache Tomcat for deploying Java web applications

• Proficiency in build tools like Maven for project ma...read more

Select 11 players from a cricket team of 15 based on binary values indicating their participation.

• Use an array of size 15 to represent players, where 1 indicates a player will play and 0 indicates they won't.

• Example array: [1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0]

• Count the number of 1s in the array to ensure only 11 players are selected.

• If there are more than 11 players with value 1, you can choose any 11 of them.

Waterfall model is a linear sequential approach, while incremental model divides the project into small increments.

• Waterfall model follows a linear and sequential approach, where each phase must be completed before moving on to the next.

• Incremental model divides the project into small increments, with each increment building upon the previous one.

• Waterfall model is less flexible to changes, as requirements are finalized early in the process.

• Incremental model allows for change...read more

Finding the maximum length of palindromic substring from an array of strings using Typescript.

• Iterate through each string in the array

• For each string, iterate through all possible substrings and check if it is a palindrome

• Keep track of the maximum length palindrome found

This code demonstrates a simple implementation of a bubble sort algorithm in Python.

• Bubble sort is a simple sorting algorithm that repeatedly steps through the list.

• It compares adjacent elements and swaps them if they are in the wrong order.

• The process is repeated until the list is sorted.

• Example: Sorting the array [5, 3, 8, 4, 2] results in [2, 3, 4, 5, 8].

• Time complexity is O(n^2) in the worst case.

In OOP, a class defines a blueprint, while objects are instances of that class, like specific rooms with unique attributes.

• Objects of the 'Room' class could be 'LivingRoom', 'Bedroom', 'Kitchen', each with unique properties.

• Each room object can have attributes like size, color, and furniture.

• Methods for the 'Room' class might include 'clean()', 'paint(color)', or 'addFurniture(furnitureItem)'.

• For example, 'LivingRoom' could have a size of 20x15 feet and be painted blue.

Compose multiple HOCs with render props in a React component

• Create a render prop component that accepts a function as a prop

• Wrap the render prop component with HOCs

• Pass the function as a prop to the HOCs

• Use the function to render the component's content

• Example: withAuth(withTheme(RenderPropComponent))

DELETE removes specific rows from a table, while TRUNCATE removes all rows and resets auto-increment values.

• DELETE is a DML command, while TRUNCATE is a DDL command.

• DELETE can be rolled back, while TRUNCATE cannot be rolled back.

• DELETE triggers ON DELETE triggers, while TRUNCATE does not trigger any triggers.

• DELETE is slower as it logs individual row deletions, while TRUNCATE is faster as it deallocates data pages.

• Example: DELETE FROM table_name WHERE condition; TRUNCATE tabl...read more

Measure exactly 4 litres using a 3-litre and a 5-litre bottle through a series of filling and pouring steps.

• Fill the 5-litre bottle completely.

• Pour water from the 5-litre bottle into the 3-litre bottle until the 3-litre bottle is full.

• This leaves 2 litres in the 5-litre bottle.

• Empty the 3-litre bottle.

• Pour the remaining 2 litres from the 5-litre bottle into the 3-litre bottle.

• Fill the 5-litre bottle again completely.

• Pour water from the 5-litre bottle into the 3-litre bottle u...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. Denormalization is the opposite process.

• Normalization involves breaking down data into smaller, more manageable tables to reduce redundancy.

• Denormalization involves combining tables to improve query performance.

• Normalization helps maintain data integrity by reducing the risk of anomalies.

• Denormalization can improve read performance but may lead to data redundancy.

• Exa...read more

Java is not called the partial OOP concept.

• Java is a fully object-oriented programming language.

• It supports all the principles of OOP such as encapsulation, inheritance, and polymorphism.

• Java allows the creation of classes, objects, and methods to implement OOP concepts.

• It provides features like abstraction and encapsulation to achieve data hiding and modularity.

• Java also supports interfaces, which are a key component of OOP.

• The misconception of Java being a partial OOP conce...read more

A simple webpage layout using HTML and CSS with a header, footer, and three cards in a row.

• Use <header> and <footer> tags for the header and footer sections.

• Create a <div> for the body content and use CSS Flexbox to align the cards.

• Each card can be a <div> with a class, styled with padding, margin, and background color.

• Example CSS: .card { flex: 1; margin: 10px; padding: 20px; background-color: #f0f0f0; }

• Ensure responsive design by using media queries for smaller screens.

Static polymorphism refers to the mechanism where the method to be called is determined at compile time.

• Method overloading is an example of static polymorphism where the method to be called is resolved at compile time based on the method signature.

• Compile-time polymorphism is another term for static polymorphism.

• Static polymorphism is achieved through function overloading and operator overloading.