400+ Software Engineer Trainee Interview Questions and Answers

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.

Answering questions related to software engineering concepts and database management systems.

• OOPs is a programming paradigm that focuses on objects and their interactions.

• The four pillars of OOPs are encapsulation, inheritance, polymorphism, and abstraction.

• Polymorphism allows objects of different types to be treated as objects of a common type.

• Method overloading is having multiple methods with the same name but different parameters.

• Method overriding is having a method in a s...read more

Reverse a singly linked list by altering the links between nodes.

• Iterate through the linked list and reverse the links between nodes.

• Keep track of the previous, current, and next nodes while reversing the links.

• Update the head of the linked list to the last node after reversal.

This interview question covers various topics in Java programming, including OOP concepts, inheritance, keywords, and implementing mathematical algorithms.

• OOP concepts include encapsulation, inheritance, polymorphism, and abstraction.

• Inheritance allows a class to inherit properties and methods from another class.

• To prevent inheritance in Java, use the 'final' keyword before the class declaration.

• Sealed, final, and static are keywords in Java with different functionalities.

• Imp...read more

No, we cannot create two columns with the same name in a relational table.

• Relational databases enforce uniqueness of column names within a table.

• Having two columns with the same name would lead to ambiguity and confusion.

• Column names are used to uniquely identify and access data in a table.

• If two columns have the same name, it would be impossible to distinguish between them.

• To avoid this, column names must be unique within a table.

Bought a pen for 50rs and sold it for 60rs. What is the percentage of profit or loss?

• Profit = Selling Price - Cost Price

• Profit = 60 - 50 = 10

• Profit Percentage = (Profit / Cost Price) * 100

• Profit Percentage = (10 / 50) * 100 = 20%

• Therefore, the percentage of profit is 20%

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.

Answers to common interview questions for Software Engineer Trainee position.

• OOPS concept is a programming paradigm that focuses on objects and their interactions.

• Arrays are a collection of elements of the same data type, while stacks and linked lists are dynamic data structures.

• Linear data structures have a sequential order, while non-linear data structures do not.

• Be prepared to code on some questions, practice coding problems beforehand.

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.

To remove redundancy in a database with repeated names, use normalization techniques.

• Identify the primary key of the table and ensure it is unique

• Create separate tables for related data to avoid repeating information

• Use foreign keys to link related tables

• Consider using indexing to improve performance

• Update existing data to conform to the new structure

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

Java is a high-level, object-oriented programming language that is platform-independent and widely used for developing applications, websites, and games.

• Developed by Sun Microsystems

• Collection of objects

• High performance and multi-threaded

• Used for developing Android apps, enterprise applications, and web applications

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

Use a 5L and a 3L jar to measure exactly 7L of water from a bucket.

• Fill the 5L jar completely from the bucket.

• Pour water from the 5L jar into the 3L jar until the 3L jar is full.

• This leaves you with 2L of water in the 5L jar.

• Empty the 3L jar back into the bucket.

• Pour the remaining 2L from the 5L jar into the 3L jar.

• Fill the 5L jar again from the bucket.

• Now pour water from the 5L jar into the 3L jar until the 3L jar is full.

• You will have exactly 7L in the bucket.

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

Typecasting is used to convert one datatype into another.

• Typecasting is the process of converting a value from one datatype to another.

• It can be done implicitly or explicitly.

• Implicit typecasting is done automatically by the compiler.

• Explicit typecasting is done manually by the programmer using casting operators.

• Examples of typecasting include converting an integer to a float, a string to an integer, etc.

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

Call by value and reference are two ways of passing arguments to functions.

• Call by value passes a copy of the argument's value to the function.

• Call by reference passes a reference to the argument's memory location to the function.

• Functions that use call by value cannot modify the original value of the argument.

• Functions that use call by reference can modify the original value of the argument.

• In some programming languages, call by reference is achieved using pointers.

• Example: ...read more

Answering questions related to programming languages, OOP, SQL queries, and easy level coding.

• I am proficient in Java and Python.

• The four pillars of OOP are encapsulation, inheritance, abstraction, and polymorphism.

• SQL queries involve selecting, inserting, updating, and deleting data from a database.

• I am comfortable with easy level coding challenges such as implementing basic algorithms or solving simple problems.

Stress is the force applied to an object, while strain is the deformation caused by that force.

• Stress is measured in units of force per unit area, such as pounds per square inch (psi) or newtons per square meter (N/m²).

• Strain is a dimensionless quantity, typically expressed as a percentage or decimal, and is calculated as the change in length or shape divided by the original length or shape.

• Stress and strain are related by a material's modulus of elasticity, which describes h...read more

To print a statement in Python, use the print() function.

• Use the print() function followed by the statement you want to print.

• Enclose the statement in quotes if it is a string.

• You can also print variables or expressions by separating them with commas.

• To print multiple statements on the same line, use the end parameter.

I am comfortable with Java and Python.

• Proficient in Java and Python programming languages

• Experience in developing web applications using Java frameworks like Spring and Hibernate

• Familiar with Python libraries like NumPy and Pandas for data analysis

• Comfortable with object-oriented programming concepts and design patterns

A database is a structured collection of data that is organized and stored for easy access, retrieval, and management.

• A database is used to store and manage large amounts of data.

• It provides a way to organize and structure data for efficient storage and retrieval.

• Databases can be relational, object-oriented, or hierarchical, depending on the data model used.

• Examples of databases include MySQL, Oracle, MongoDB, and SQLite.

Answers to interview questions for Software Engineer Trainee

• Primary foreign key is a column in a table that is used to link to the primary key of another table

• ACID properties are Atomicity, Consistency, Isolation, and Durability which ensure database transactions are reliable

• To return 3rd maximum salary, use the LIMIT and OFFSET clauses in SQL

• SQL join is used to combine data from two or more tables based on a related column

• IN in SQL is used to specify multiple values in a WHE...read more