Bobble AI Data Annotator Interview Questions and Answers

Regex for email validation

• Start with a string of characters followed by @ symbol

• Followed by a string of characters and a period

• End with a string of characters with a length of 2-6 characters

• Allow for optional subdomains separated by periods

• Disallow special characters except for . and _ in username

Print prime numbers in a given range and optimize the solution.

• Use Sieve of Eratosthenes algorithm to generate prime numbers efficiently

• Start with a boolean array of size n+1, mark all as true

• Loop through the array and mark all multiples of each prime as false

• Print all the indexes that are still marked as true

Find angle between hour and minute hand in a clock given the time.

• Calculate the angle made by the hour hand with respect to 12 o'clock position

• Calculate the angle made by the minute hand with respect to 12 o'clock position

• Find the difference between the two angles and take the absolute value

• If the angle is greater than 180 degrees, subtract it from 360 degrees to get the smaller angle

To un-hash a string, use a reverse algorithm to convert the hash back to the original string.

• Create a reverse algorithm that takes the hash as input and outputs the original string

• Use the same logic as the hash function but in reverse order

• If the hash function used a specific algorithm, use the inverse of that algorithm to un-hash the string

Probability of a horse going out of a chessboard in 'n' steps.

• The total number of possible moves for a horse is 8.

• The probability of going out of the board depends on the position of the horse.

• For example, if the horse is at a corner, the probability of going out of the board is higher.

• The probability can be calculated using combinatorics and geometry.

I am an avid traveler and have visited over 20 countries

• I love experiencing new cultures and trying new foods

• I have backpacked through Europe and Asia

• I have volunteered in orphanages in Cambodia and Nepal

Mobile advertising platform

• Adtech

• Mobile marketing

• App monetization

Maximum sub sequence sum in an array

• Use Kadane's algorithm

• Initialize max_so_far and max_ending_here to 0

• Iterate through the array and update max_ending_here and max_so_far

• Return max_so_far

Endianness refers to the byte order of a system. It determines how multi-byte data types are stored in memory.

• Little-endian systems store the least significant byte first, while big-endian systems store the most significant byte first.

• Endianness can affect the way data is transmitted between systems.

• To determine the endianness of a system, you can use the byte order mark (BOM) or write a test program that checks the by...read more

Sort an array of 0's and 1's only.

• Use two pointers, one at the beginning and one at the end of the array.

• Swap 0's from the beginning with 1's from the end until the pointers meet.

• Alternatively, use a counting sort algorithm to count the number of 0's and 1's and then reconstruct the array.

Heaps are data structures used to efficiently find the maximum or minimum element in a collection.

• Max heap: parent nodes are always greater than or equal to child nodes

• Min heap: parent nodes are always smaller than or equal to child nodes

• Heaps are commonly used in priority queues and sorting algorithms

• Heap operations include insert, delete, and extract max/min

• Example: An array [3, 8, 2, 5, 1, 4, 6] can be represented a

Find 3 numbers in an array where a+b=c.

• Loop through the array and check for all possible combinations of a and b.

• Use a hash table to store the values of a and b, and check if c is present in the hash table.

• Sort the array and use two pointers to find a and b, and then check if their sum equals c.

Algorithms for manipulating arrays and strings in coding

• Use sorting algorithms like quicksort and mergesort for arrays

• Use string manipulation functions like substring and replace for strings

• Use dynamic programming for optimizing solutions to array and string problems

Designing a large scale Ad Server

• Use distributed systems for scalability

• Implement caching for faster ad delivery

• Ensure high availability and fault tolerance

• Use real-time bidding for efficient ad placement

• Implement fraud detection mechanisms

• Ensure compliance with privacy regulations

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Start from the first element and compare it with the next element

• If the first element is greater than the next element, swap them

• Repeat this process for all elements in the list

• Continue this process until no more swaps are needed

A Turing Machine is a theoretical device that can simulate any algorithmic computation.

• It was proposed by Alan Turing in 1936 as a model for computation.

• It consists of a tape, a head that can read and write symbols on the tape, and a set of rules for transitioning between states.

• It can simulate any algorithmic computation, making it a powerful tool for theoretical computer science.

• It is often used as a theoretical basi...read more

A hash function is a mathematical function that converts input data of arbitrary size into a fixed-size output.

• Hash functions are used to index data in hash tables.

• They are also used in cryptography to securely store passwords.

• Examples of hash functions include MD5, SHA-1, and SHA-256.

I am impressed with the company's reputation and growth potential, and I believe my skills and experience align well with the job requirements.

• I have researched the company and am impressed with its reputation and growth potential

• I believe my skills and experience align well with the job requirements

• I am excited about the opportunity to work with a talented team and contribute to the company's success

I have the necessary skills, experience, and passion to excel in this role.

• I have a proven track record of success in similar roles.

• I am a quick learner and adaptable to new situations.

• I am passionate about this industry and eager to contribute to its growth.

• I have excellent communication and teamwork skills.

• I am committed to delivering high-quality work and exceeding expectations.

I would prioritize completing my current assignment and then discuss the transfer with my supervisor to ensure a smooth transition.

• I would communicate with my supervisor to understand the urgency of the transfer

• I would prioritize completing my current assignment to the best of my ability

• I would discuss the transfer with my supervisor to ensure a smooth transition

• I would try to complete as much work as possible before l...read more

A batsman can score a maximum of 264 runs in an ODI.

• The maximum number of runs a batsman can score in an ODI is limited by the number of balls bowled and the number of boundaries hit.

• The maximum number of balls bowled in an ODI is 300, assuming no extras are bowled.

• If a batsman hits a boundary off every ball they face, they can score a maximum of 240 runs.

• If a batsman hits sixes off every ball they face, they can score...read more

Solving two jug problems to obtain a specified amount of water using differently sized jugs.

• Understand the capacity of each jug

• Determine the amount of water needed

• Fill one jug with water and pour it into the other jug

• Repeat until the desired amount is reached

• Use the remaining water in the larger jug to measure the remaining amount needed

• Consider the possibility of multiple solutions