Celigo Junior Software Developer Interview Questions and Answers

Code to delete duplicate nodes in a sorted linked list

• Traverse the linked list and compare adjacent nodes

• If nodes are equal, delete one of them

• Repeat until all duplicates are removed

Printing all root to leaf paths in a binary search tree

• Traverse the tree recursively and keep track of the current path

• When a leaf node is reached, add the current path to the list of paths

• Print all the paths in the list

• Use an array of strings to store the paths

Find two integers in an array whose sum is closest to zero.

• Sort the array in ascending order.

• Initialize two pointers at the beginning and end of the array.

• Move the pointers towards each other until the sum is closest to zero.

Count set bits in a 32-bit integer in linear time

• Use bit manipulation to count set bits

• Divide the integer into 16-bit chunks and count set bits in each chunk

• Use lookup tables to count set bits in each 8-bit chunk

• Use parallel processing to count set bits in multiple integers simultaneously

To determine the width of a binary tree using breadth-wise traversal, we need to count the number of nodes at each level.

• Perform a breadth-first traversal of the binary tree

• Count the number of nodes at each level

• Keep track of the maximum number of nodes seen at any level

• Return the maximum number of nodes seen

Files are preferred over databases for certain types of data and applications.

• Files are faster for small amounts of data.

• Files are easier to manage and backup.

• Files are more flexible for certain types of data, such as images or videos.

• Databases are better for complex data relationships and queries.

• Databases are more secure and scalable for large amounts of data.

• The choice between files and databases depends on the spec

I have contributed to my projects by developing and implementing new features, fixing bugs, and improving overall performance.

• Developed and implemented new features

• Fixed bugs and issues

• Improved overall performance

• Collaborated with team members to ensure project success

• Provided technical support and troubleshooting assistance

I encourage open communication and collaboration to identify and solve problems within the team.

• Encourage open communication and active listening

• Identify the root cause of the problem

• Brainstorm solutions as a team

• Assign tasks and follow up on progress

• Evaluate the effectiveness of the solution

• Provide constructive feedback

• Celebrate successes and learn from failures

I expect a company that values innovation, growth opportunities, and work-life balance.

• Opportunities for professional development and growth

• A culture that encourages innovation and creativity

• A healthy work-life balance

• Clear communication and transparency

• Competitive compensation and benefits

• Collaborative and supportive team environment

Yes, I am planning to pursue a Master's degree in Computer Science.

• I am interested in specializing in Artificial Intelligence.

• I have already researched and shortlisted a few universities.

• I plan to apply for the next academic year.

• I believe higher studies will help me gain a deeper understanding of the field and advance my career.

I am very flexible in my professional life and can adapt to changing situations easily.

• I am open to learning new technologies and skills

• I can work in different environments and with different teams

• I am willing to take on new challenges and responsibilities

• I can adjust my work schedule to meet project deadlines

• I am comfortable with remote work and flexible work arrangements

I am a software engineer with experience in developing web applications and a passion for problem-solving.

• Experienced in developing web applications using languages such as Java, Python, and JavaScript

• Proficient in using frameworks such as Spring, Django, and React

• Strong problem-solving skills and ability to work in a team environment

• Passionate about learning new technologies and keeping up with industry trends

Find the minimum and maximum values in an array in a single traversal.

• Initialize min and max variables with the first element of the array

• Iterate through the array and update min and max if a smaller or larger value is found

• Return the min and max values

The maximum number of squares on a chessboard is 64.

• The chessboard has 64 squares in total.

• The number of squares on a chessboard can be calculated using the formula n^2, where n is the number of rows or columns.

• In this case, n = 8 (8 rows and 8 columns), so the maximum number of squares is 8^2 = 64.

C++ is a programming language. Deep copy creates a new object and copies all values, while shallow copy creates a reference to the original object.

• C++ is a general-purpose programming language

• Deep copy creates a new object with its own copy of the data

• Shallow copy creates a reference to the original object

• Deep copy is safer but can be slower and consume more memory

• Shallow copy is faster but can lead to unexpected behav

Pre initialization refers to the process of initializing variables or objects before they are used in a program.

• Pre initialization helps avoid errors or unexpected behavior caused by using uninitialized variables.

• It is a good practice to pre initialize variables with default values.

• Pre initialization can be done using constructors, default values, or initialization blocks.

• Example: int count = 0; initializes the variabl

Reverse a linked list with and without using Recursion

• Iterative approach: Use three pointers to reverse the links between nodes

• Recursive approach: Recursively reverse the rest of the list and then fix the links

Polymorphism refers to the ability of an object to take on many forms. The diamond problem occurs in multiple inheritance.

• Polymorphism can be achieved through method overloading and method overriding.

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

• Method overriding occurs when a subclass provides a specific implementation of a method already defined in its superclass.

• The diamond p...read more

The program should differentiate between integers and characters when using the assignment operator (=).

• Check the data type of the variable before assigning a value.

• Use conditional statements to perform different actions based on the data type.

• For integers, assign the value directly. For characters, convert the character to its ASCII value and assign it.

Sort an array by moving all zeroes to the end.

• Iterate through the array and move all non-zero elements to the front.

• Count the number of zeroes encountered and append them at the end of the array.

• Use two pointers to swap elements and maintain the order.

The number of VTables created in a class hierarchy depends on the number of virtual functions and the number of derived classes.

• VTables are used in object-oriented programming languages to implement dynamic dispatch.

• Each class with at least one virtual function has its own VTable.

• Derived classes inherit the VTable of their base class and add their own entries for any additional virtual functions.

• The total number of VTa...read more

List is preferred when frequent insertion and deletion is required. Vector is preferred when random access is required.

• List is implemented as a doubly-linked list, allowing for efficient insertion and deletion at any position.

• Vector is implemented as a dynamic array, allowing for efficient random access.

• Use List when the number of elements is expected to change frequently and the order of elements matters less.

• Use Vect...read more

The given string needs to be reversed and the words need to be rearranged.

• Split the string into an array of words

• Reverse the array

• Join the array elements with a space in between

Design a parking lot with Logic Flow Diagram, E-R diagram, DB tables with relations, and commands for transactions.

• Identify the types of vehicles that will use the parking lot

• Determine the number of parking spaces needed for each vehicle type

• Create a flow diagram to show the process of entering and exiting the parking lot

• Design an E-R diagram to show the relationships between entities such as vehicles, parking spaces, ...read more

To find min and max of an array in one traversal, initialize min and max to first element and compare with rest.

• Initialize min and max to first element of array

• Traverse the array and compare each element with min and max

• Update min and max accordingly

• Return min and max

Given a chessboard, find the maximum number of squares present.

• Start with the smallest square and count all possible squares

• Use the formula n*(n+1)*(2n+1)/6 to find the total number of squares in an n x n chessboard

• Add up the squares of all sizes from 1 to n to get the maximum number of squares

• For example, an 8 x 8 chessboard has 204 squares

C++ is a high-level programming language used for developing system software, application software, device drivers, and video games.

• C++ was developed by Bjarne Stroustrup in 1983.

• It is an extension of the C programming language.

• C++ supports object-oriented programming, generic programming, and low-level memory manipulation.

• It is used in developing operating systems, browsers, databases, and more.

• Examples of popular sof...read more

Deep copy creates a new object with a new memory address, while shallow copy creates a new reference to the same memory address.

• Deep copy duplicates the object and all its nested objects, while shallow copy only duplicates the top-level object.

• Deep copy is slower and more memory-intensive than shallow copy.

• Shallow copy can lead to unexpected behavior if the original object is modified.

• In Python, deep copy can be achiev...read more

Preinitialization is the process of initializing data or objects before they are actually needed.

• Preinitialization can improve performance by reducing the time needed to initialize data or objects when they are actually needed.

• It can also help to avoid delays or interruptions during runtime.

• Examples of preinitialization include preloading data into memory, initializing objects in advance, and caching frequently used da

Polymorphism can be achieved through method overloading, method overriding, and interfaces. Multiple inheritance can be solved using interfaces.

• Method overloading allows multiple methods with the same name but different parameters

• Method overriding allows a subclass to provide its own implementation of a method already defined in its superclass

• Interfaces provide a way to achieve multiple inheritance by allowing a class ...read more

WAP to generate a matrix from a given tree.

• Create a 2D array to store the matrix

• Traverse the tree and fill the matrix accordingly

• Use BFS or DFS to traverse the tree

• The matrix will be symmetric along the diagonal

Primary key is a column or set of columns that uniquely identifies each row in a table. Unique key is a constraint that ensures uniqueness of values in a column or set of columns.

• Primary key is used to enforce data integrity and ensure that each row in a table can be uniquely identified.

• Unique key is used to ensure that no two rows in a table have the same values in a column or set of columns.

• Primary key can be a singl...read more

Yes, a unique key can be a primary key.

• A primary key is a unique identifier for a record in a table.

• A unique key is a constraint that ensures the values in a column are unique.

• A unique key can be used as a primary key if it meets the requirements.

• A primary key cannot have NULL values, while a unique key can have one NULL value.

Foreign key is a column in a table that refers to the primary key of another table.

• It establishes a relationship between two tables.

• It ensures referential integrity.

• It can be null, but only if it is defined as nullable.

• It helps in joining tables.

• Example: Customer table has a foreign key to the Order table's primary key.

• Example: Order table's foreign key can be null if the order has not been placed by any customer yet.

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

• Normalization involves breaking down a database into smaller, more manageable tables.

• It helps to eliminate data redundancy and inconsistencies.

• Normalization ensures that each table has a primary key and that data is stored in a logical and consistent manner.

• It improves data integrity and reduces the likelihood ...read more

Normalized form is better for data consistency and scalability.

• Normalized form reduces data redundancy and ensures data consistency.

• Normalized form allows for easier scalability and maintenance.

• Single table/2 tables may be appropriate for small, simple datasets.

• Normalized form may require more complex queries to retrieve data.

• Normalized form may require more storage space due to additional tables.

• Example: Normalized fo...read more

Create a database for Indian Premier League (IPL)

• Identify entities like teams, players, matches, venues, etc.

• Create tables for each entity with relevant attributes

• Establish relationships between tables using foreign keys

• Add constraints like unique, not null, default values, etc.

• Populate tables with data from reliable sources

Query to find player with maximum runs in a match on given date and venue

• Use MAX() function to find maximum runs

• Join tables for player name, match details and runs scored

• Filter by given date and venue

• Order by runs scored and limit to 1 result

Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.

• Inheritance allows for code reuse and promotes modularity.

• The class that is being inherited from is called the superclass or base class.

• The class that inherits from the superclass is called the subclass or derived class.

• The subclass can access the public and protected members of the superclass.

• Inhe...read more

Regular expressions in PHP are powerful tools for pattern matching and manipulating strings.

• Regular expressions are defined using the preg_match() function in PHP.

• They are used to search, replace, and validate strings based on specific patterns.

• Regex patterns consist of a combination of characters and special symbols.

• Modifiers can be added to the pattern to control the matching behavior.

• Common regex functions in PHP in...read more

Polymorphism is the ability of an object to take on many forms. It allows objects of different classes to be treated as the same type.

• Polymorphism allows a single interface to be used for different types of objects.

• It enables code reusability and flexibility in object-oriented programming.

• For example, a parent class 'Animal' can have multiple child classes like 'Dog', 'Cat', and 'Bird'. They can all be treated as 'Anim...read more

Sort the individual digits of a 10 digit number.

• Convert the number to a string to access individual digits

• Use a sorting algorithm to sort the digits

• Convert the sorted digits back to a number

The code for finding the Lowest Common Ancestor (LCA) in a Binary Search Tree (BST).

• Start from the root node and compare it with the given two nodes.

• If both nodes are smaller than the current node, move to the left subtree.

• If both nodes are greater than the current node, move to the right subtree.

• If one node is smaller and the other is greater, then the current node is the LCA.

• Continue this process until the LCA is fou

A DBMS for managing college faculty, professors, courses, and students.

• The DBMS should have tables for faculty, professors, courses, and students.

• Each table should have appropriate attributes to store relevant information.

• Relationships can be established between tables using foreign keys.

• Queries can be used to retrieve information about faculty, professors, courses, and students.

• The DBMS can be used to track enrollment

I was actively involved in coding competitions, hackathons, and programming clubs during college.

• Participated in coding competitions such as ACM ICPC and Codeforces

• Attended hackathons to work on real-world projects and improve problem-solving skills

• Joined programming clubs to collaborate with peers and learn new technologies

Yes, I believe in seeking help when stuck in a problem as it leads to faster resolution and learning.

• I believe in collaborating with team members to brainstorm solutions

• I am not afraid to ask for help from more experienced developers

• I utilize online resources like Stack Overflow or documentation when needed

Teamwork is collaborating with others towards a common goal, utilizing each member's strengths and skills.

• Collaborating with others towards a common goal

• Utilizing each member's strengths and skills

• Communicating effectively and openly

• Respecting and valuing diverse perspectives

• Sharing responsibilities and supporting each other

• Celebrating successes as a team

When faced with an unsolvable problem, I break it down, research, seek help, experiment, and iterate until a solution is found.

• Break down the problem into smaller, manageable parts

• Research and gather information related to the problem

• Seek help from colleagues, online communities, or experts

• Experiment with different approaches or solutions

• Iterate and refine the solution based on feedback and results

In 5 years, I see myself as a senior software developer leading a team of developers on innovative projects.

• Leading a team of developers on innovative projects

• Senior software developer role

• Continuing to learn and grow in the field