Lumiq Interview Questions and Answers

Maximize the number of vaccines administered on a specific day while adhering to certain rules.

• Given n days, maxVaccines available, and a specific dayNumber, distribute vaccines to maximize on dayNumber

• Administer positive number of vaccines each day with a difference of 1 between consecutive days

• Ensure sum of vaccines distributed does not exceed maxVaccines

• Output the maximum number of vaccines administered on dayNumber for each test case

Find the sum of the subarray with the maximum sum among all subarrays in an array of integers.

• Iterate through the array and keep track of the current sum and maximum sum.

• If the current sum becomes negative, reset it to 0.

• Return the maximum sum found.

Deadlocks in operating systems occur when two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlocks happen when processes hold resources and wait for others, creating a circular wait.

• Four conditions must hold for a deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait.

• Deadlocks can be resolved using methods like prevention, avoidance, detection, and recovery.

• Examples of deadlock resolution ...read more

Coalesce is used to select the first non-null value from a set of columns. Repartition is used to shuffle data across nodes.

• Coalesce is a function that returns the first non-null value from a set of columns.

• Repartition is used to shuffle data across nodes to increase parallelism.

• Coalesce reduces the number of columns in a DataFrame.

• Repartition increases or decreases the number of partitions in a DataFrame.

• Coalesce is used to merge multiple columns into one.

• Repartition is used...read more

Bcrypt lib is a library used for hashing passwords securely in software projects.

• Bcrypt lib is commonly used in software projects to securely hash passwords before storing them in a database.

• It helps protect user passwords from being easily compromised in case of a data breach.

• Bcrypt uses a salt to add randomness to the hashing process, making it more difficult for attackers to crack passwords.

• Example: bcrypt.hashSync('password123', 10); // hashes the password 'password123' w...read more

Optimizing Spark jobs involves tuning various parameters such as memory allocation, partitioning, and caching.

• Increase memory allocation for executors and driver

• Partition data appropriately to avoid skewness

• Cache frequently accessed data to avoid recomputation

• Use broadcast variables for small data sets

• Avoid shuffling data unnecessarily

• Use appropriate serialization format

• Use appropriate hardware for cluster

• Monitor and optimize resource utilization

Find the 5th highest salary using SQL.

• Use the ORDER BY clause to sort the salaries in descending order.

• Use the LIMIT clause to limit the result to the 5th highest salary.

• Use a subquery to exclude the top 4 salaries and retrieve the 5th highest salary.

To create and print a box in HTML, use the <div> element with CSS styling for borders and dimensions.

• Use the <div> element to create a box in HTML.

• Apply CSS styling to set the dimensions (width, height) of the box.

• Use CSS properties like border, padding, and margin to create the box outline.

• Example: <div style='width: 100px; height: 100px; border: 1px solid black;'></div>