Snapdeal Front end Engineer Interview Questions, Process, and Tips

PreOrder traversal without recursion is done using a stack to simulate the function call stack.

• Create an empty stack and push the root node onto it.

• While the stack is not empty, pop a node from the stack and process it.

• Push the right child of the popped node onto the stack if it exists.

• Push the left child of the popped node onto the stack if it exists.

Yes

• Create an empty binary search tree (BST)

• Loop over the unsorted array

• For each element, insert it into the BST using the appropriate insertion logic

• Repeat until all elements are inserted

• The resulting BST will be built from the unsorted array

The question asks to find two elements in an array whose sum is equal to a given number.

• Iterate through the array and for each element, check if the difference between the given number and the current element exists in the array.

• Use a hash set to store the elements as you iterate through the array for efficient lookup.

• Return the pair of elements if found, otherwise return a message indicating no such pair exists.

There are two types of triggers: DML triggers and DDL triggers.

• DML triggers are fired in response to DML (Data Manipulation Language) statements like INSERT, UPDATE, DELETE.

• DDL triggers are fired in response to DDL (Data Definition Language) statements like CREATE, ALTER, DROP.

• Examples: A DML trigger can be used to log changes made to a table, while a DDL trigger can be used to enforce certain rules when a table is alt

Yes, triggers can be used with select statements in SQL.

• Triggers are database objects that are automatically executed in response to certain events, such as insert, update, or delete operations.

• While triggers are commonly used with insert, update, and delete statements, they can also be used with select statements.

• Using triggers with select statements allows you to perform additional actions or validations before or af...read more

Indexing in MySQL improves query performance. There are several types of indexing in MySQL.

• Indexes are used to quickly locate data without scanning the entire table.

• Types of indexing in MySQL include B-tree, hash, full-text, and spatial indexes.

• B-tree indexes are the most common and suitable for most use cases.

• Hash indexes are used for exact match lookups.

• Full-text indexes are used for searching text-based data efficie...read more

Engines in MySQL are the underlying software components that handle storage, indexing, and querying of data.

• MySQL supports multiple storage engines, each with its own strengths and features.

• Some commonly used engines in MySQL are InnoDB, MyISAM, and Memory.

• InnoDB is the default engine in MySQL and provides support for transactions and foreign keys.

• MyISAM is known for its simplicity and speed but lacks transaction suppo...read more

Yes, a constructor can be private.

• A private constructor can only be accessed within the class itself.

• It is often used in singleton design pattern to restrict object creation.

• Private constructors are also useful for utility classes that only contain static methods.

Merge sort algorithm can be used to sort the balls in each basket and then merge the sorted baskets.

• Apply merge sort algorithm to sort the balls in each basket

• Merge the sorted baskets to get the final sorted order

• Use recursion to implement merge sort

• Time complexity of merge sort is O(nlogn)

Mutual Exclusion is a technique to ensure that only one process at a time can access a shared resource.

• It prevents race conditions and ensures data consistency.

• It can be implemented using locks, semaphores, or monitors.

• Examples include critical sections in multi-threaded programs and database transactions.

• It can lead to performance issues if not implemented efficiently.

Multithreading is the ability of a CPU to execute multiple threads concurrently. A process is an instance of a program in execution.

• Multithreading allows multiple threads to run concurrently within a single process.

• Threads share the same memory space and resources of the process they belong to.

• Processes are independent of each other and have their own memory space and resources.

• Threads are lightweight compared to proce...read more

Semaphore is a synchronization object used to control access to a shared resource.

• Semaphore is used to limit the number of threads accessing a shared resource.

• It can be used to implement critical sections and avoid race conditions.

• Semaphore can be binary or counting, depending on the number of resources available.

• Examples of semaphore in programming languages include Java's Semaphore class and Python's threading.Semaph

Wait for completion of all threads and join them into a single thread.

• Use join() method to wait for completion of each thread.

• Create a new thread and call start() method to start the execution of all threads.

• Use sleep() method to pause the execution of the current thread until all threads complete their execution.

To delete 95,000 records with limited local memory, use batch processing and delete in chunks.

• Use batch processing to delete records in chunks

• Delete records in descending order of their IDs to avoid index fragmentation

• Commit the transaction after deleting each batch to avoid long-running transactions

• Consider archiving the deleted records instead of permanently deleting them

Program in C to implement a function 'sum' that performs integer addition, float addition, and string concatenation based on the input arguments.

• Define the function 'sum' with two arguments of type 'void *'.

• Use 'if-else' statements to check the data type of the arguments.

• Perform integer addition if both arguments are of type 'int'.

• Perform float addition if both arguments are of type 'float'.

• Concatenate the strings if b...read more

SQL query for creating tables

• Use CREATE TABLE statement

• Specify table name and column names with data types

• Add constraints like primary key, foreign key, etc.

• Example: CREATE TABLE customers (id INT PRIMARY KEY, name VARCHAR(50), email VARCHAR(50))

Nested tables are tables within tables, used to organize and store complex data structures.

• Nested tables are commonly used in databases to store arrays of data within a single row of a table.

• They can also be used in programming languages to create multidimensional arrays.

• Accessing data within a nested table requires using multiple levels of indexing.

• Nested tables can improve data organization and simplify complex data

Views are virtual tables that display data from one or more tables in a database.

• Views are created using SELECT statements.

• They can be used to simplify complex queries.

• They can also be used to restrict access to sensitive data.

• Views do not store data themselves, but rather display data from underlying tables.

• Changes made to the underlying tables are reflected in the view.

I am a software developer with experience in multiple programming languages and a passion for problem-solving.

• Proficient in Java, Python, and C++

• Experience with web development using HTML, CSS, and JavaScript

• Familiarity with Agile development methodologies

• Strong problem-solving and analytical skills

• Excellent communication and teamwork abilities

Postfix expression can be evaluated using a stack data structure.

• Create an empty stack

• Scan the expression from left to right

• If the scanned character is an operand, push it onto the stack

• If the scanned character is an operator, pop two operands from the stack, perform the operation and push the result back

• Repeat until the end of the expression

• The final result is the top of the stack

In 5 years, I see myself as a senior software developer leading a team of developers to create innovative solutions.

• Leading a team of developers to create innovative solutions

• Continuing to learn and stay up-to-date with new technologies

• Contributing to the growth and success of the company

• Mentoring and coaching junior developers

• Taking on more responsibilities and challenges

Ebay is a leading e-commerce platform with a global reach and a diverse range of products.

• Ebay has a large and diverse customer base, providing opportunities to work on a variety of projects.

• The company has a strong focus on innovation and technology, which aligns with my interests and skills.

• Ebay offers a dynamic and fast-paced work environment, which I find exciting and challenging.

• The company has a strong reputation...read more

I want to join eBay because of its global reach, innovative technology, and strong company culture.

• Global reach: eBay operates in multiple countries, allowing me to work on projects with a global impact.

• Innovative technology: eBay is known for its cutting-edge technology and continuous innovation, which excites me as a software engineer.

• Strong company culture: eBay values diversity, collaboration, and personal growth, ...read more