30+ Interview Questions and Answers

The maximum number of corn fields possible in a 10m×10m square field without sharing edges is 25.

• The maximum number of corn fields is achieved by placing them in a diagonal pattern across the field.

• Each corn field will have 4 wheat fields surrounding it to ensure no two corn fields share an edge.

• The total number of corn fields possible in this arrangement is 25.

The neighbourhood with the biggest median price difference between superhosts and non superhosts is X.

• Calculate the median price for superhosts and non superhosts in each neighbourhood

• Find the neighbourhood with the largest difference in median prices between superhosts and non superhosts

• Example: Neighbourhood X has a median price of $200 for superhosts and $150 for non superhosts, resulting in a $50 difference

Find numbers that appear at least three times consecutively in any order.

• Use a window function to track consecutive numbers

• Filter the result to only include numbers that appear at least three times consecutively

• Return the result table in any order

Find the maximum number of vowels in any substring of length k in a given string.

• Iterate through the string with a sliding window of size k, counting vowels in each substring.

• Keep track of the maximum vowel count encountered.

• Return the maximum vowel count found.

Statistical significance refers to the likelihood that a result or relationship is not due to chance.

• Statistical significance is a measure of the probability that a relationship between variables is not due to random chance.

• Hypothesis testing is a common method to determine statistical significance by comparing observed data to what would be expected by chance.

• A p-value is used to determine statistical significance, with a lower p-value indicating stronger evidence against th...read more

I cross-referenced the conflicting information with other reliable sources and consulted with relevant stakeholders to determine the accuracy.

• Cross-referenced conflicting information with other reliable sources

• Consulted with relevant stakeholders for clarification

• Analyzed the context and credibility of each source before making a decision

It is difficult to accurately estimate the number of people wearing spectacles in Delhi without specific data.

• Population of Delhi is around 20 million, so a rough estimate could be based on the global average of 25% of the population wearing spectacles.

• Factors such as age demographics, income levels, and access to healthcare facilities can also influence the number of people wearing spectacles.

• Survey data or market research reports on eyewear usage in Delhi could provide more...read more

It is impossible to accurately estimate the number of red lights in Bangalore without specific data.

• The number of red lights in a city can vary based on factors such as population density, traffic flow, and urban planning.

• One would need access to official records or data from the city's transportation department to make a more accurate estimation.

• Factors like new road constructions, traffic patterns, and signal upgrades can also impact the number of red lights in a city.

Solved a complex problem with limited information by breaking it down into smaller parts and conducting thorough research.

• Identified key components of the problem

• Conducted thorough research to gather relevant information

• Utilized critical thinking and problem-solving skills to connect the dots

• Consulted with experts or colleagues for additional insights

• Tested different solutions to find the most effective one

The angle between the minute and hour hands of a clock at 2:20 is 50 degrees.

• Calculate the angle formed by the hour hand from 12 o'clock to the current time (2:20)

• Calculate the angle formed by the minute hand from 12 o'clock to the current time (20 minutes past the hour)

• Subtract the smaller angle from the larger angle to get the angle between the minute and hour hands

Flask is a lightweight web framework for Python that allows you to easily handle HTTP requests.

• Create a Flask application by importing the Flask class

• Define routes using the @app.route decorator

• Handle different types of requests (GET, POST, etc.) using route functions

• Return responses using the jsonify function for JSON data

• Run the Flask application using the app.run() method

To improve the overall quality of the process, I would focus on identifying root causes, implementing process improvements, and monitoring results.

• Conduct a thorough analysis to identify the root causes of the quality issues

• Collaborate with stakeholders to develop and implement process improvements

• Establish key performance indicators (KPIs) to monitor the effectiveness of the changes

• Regularly review and adjust the process based on feedback and data

• Provide training and support...read more

Check if a sentence is a palindrome or not.

• Remove all non-alphanumeric characters and convert to lowercase.

• Compare the original sentence with its reverse to check for palindrome.

• Example: 'A man, a plan, a canal, Panama' is a palindrome sentence.

The number of tennis balls that can fit into a school bus depends on the size of the bus and the size of the tennis balls.

• Calculate the volume of the school bus and the volume of a tennis ball to determine how many can fit

• Consider the packing efficiency of the tennis balls to account for empty space

• Assume a standard size for the school bus and tennis balls for easier calculation

Use memoization, virtual DOM, and shouldComponentUpdate to avoid unnecessary rerenders and improve performance.

• Implement memoization to store the result of expensive function calls and avoid recalculating them.

• Use virtual DOM to efficiently update only the parts of the UI that have changed.

• Override shouldComponentUpdate to prevent unnecessary rerenders by comparing current and next props/state.

Optimizing performance of a Nodejs app involves various techniques to improve speed and efficiency.

• Use asynchronous programming to handle multiple requests efficiently

• Implement caching to reduce redundant database queries

• Optimize code by removing unnecessary loops and function calls

• Use a load balancer to distribute traffic evenly across multiple servers

• Monitor and analyze performance using tools like New Relic or Datadog

Program to maximize money from robbing 9 houses without triggering alarm for consecutive robberies

• Create a list of money in each house

• Use dynamic programming to keep track of maximum money robbed without triggering alarm

• Consider robbing or skipping each house based on previous robberies

• Example: houses = [10, 20, 15, 25, 10, 30, 50, 5, 40]

To measure 4 liters from 5 and 3 liter vessels, fill 3 liter vessel, pour into 5 liter vessel, refill 3 liter vessel, pour into 5 liter vessel until it is full.

• Fill the 3 liter vessel completely

• Pour the water from the 3 liter vessel into the 5 liter vessel

• Refill the 3 liter vessel

• Pour the water from the 3 liter vessel into the 5 liter vessel until it is full

The chord is a line segment connecting two points on a circle. The diameter is a chord that passes through the center of the circle. The radius is the distance from the center to any point on the circle.

• Chord is a line segment connecting two points on a circle

• Diameter is a chord that passes through the center of the circle

• Radius is the distance from the center to any point on the circle

• Chord length can be calculated using the Pythagorean theorem

Merge two sorted linked lists by creating a linked list class and method to generate linked lists from scratch.

• Create a Node class with data and next pointer

• Create a LinkedList class with methods to insert nodes and merge two lists

• Iterate through both lists and compare nodes to merge them in sorted order

A sector is a portion of a circle enclosed by two radii and an arc. LCM stands for Least Common Multiple.

• A sector is a part of a circle enclosed by two radii and an arc

• The area of a sector can be calculated using the formula (θ/360) * π * r^2, where θ is the central angle and r is the radius

• LCM is the smallest multiple that is divisible by two or more numbers

• LCM is used in various mathematical calculations such as adding and subtracting fractions with different denominators

Callbacks, Promises, async await are asynchronous programming concepts in JavaScript.

• Callbacks are functions passed as arguments to another function to be executed later.

• Promises are objects representing the eventual completion or failure of an asynchronous operation.

• async await is a syntax for writing asynchronous code that looks synchronous, making it easier to read and maintain.

• Example: Using a callback to handle the result of an asynchronous API call.

• Example: Creating a P...read more

Develop a recommendation system for ranking developers for job positions.

• Collect data on developer skills, experience, projects, and job preferences

• Use collaborative filtering to recommend job positions based on similar developers

• Implement content-based filtering to recommend jobs based on developer skills and preferences

• Utilize machine learning algorithms to continuously improve recommendations

• Consider incorporating feedback from developers and employers to enhance the syste...read more

Optimising React involves code splitting, lazy loading, using PureComponent, avoiding unnecessary re-renders, and using memoization.

• Use code splitting to load only necessary components

• Implement lazy loading for components that are not immediately needed

• Utilize PureComponent to prevent unnecessary re-renders

• Avoid unnecessary re-renders by using shouldComponentUpdate or React.memo

• Use memoization techniques like useMemo or useCallback for expensive computations

Classes are reference types, while structs are value types in Swift.

• Classes are reference types, meaning they are passed by reference, while structs are value types, passed by value.

• Classes support inheritance, while structs do not.

• Classes have deinitializers, while structs do not.

• Classes can have reference counting for memory management, while structs do not.

• Example: Class - Person, Struct - Point

useRef hook is used to persist a mutable value across renders without causing a re-render.

• Used to store mutable values that do not trigger re-renders.

• Commonly used for accessing DOM elements or storing previous values.

• Does not cause a re-render when the value changes.

A callback is a function that is passed as an argument to another function and is executed after the completion of that function.

• Callbacks are commonly used in asynchronous programming to handle tasks that take time to complete.

• They allow for functions to be executed once a certain task is completed, without blocking the rest of the code.

• Example: setTimeout function in JavaScript takes a callback function as an argument to be executed after a specified time.

ARC stands for Automatic Reference Counting, a memory management system used in iOS development. Retain count is the number of references to an object.

• ARC is a memory management system in iOS that automatically tracks and manages memory usage.

• Retain count is the number of strong references to an object, which determines when the object should be deallocated.

• When an object's retain count reaches 0, it is deallocated from memory to free up resources.

• ARC helps prevent memory lea...read more

Convert decimal number to binary representation using division and remainder method.

• Start by dividing the decimal number by 2 and noting down the remainder.

• Continue dividing the quotient by 2 until the quotient is 0.

• The remainders obtained in reverse order will give the binary representation.

Market research types include primary research, secondary research, qualitative research, quantitative research, and exploratory research.

• Primary research involves collecting data directly from the source, such as surveys, interviews, and observations.

• Secondary research involves analyzing existing data sources, such as reports, articles, and databases.

• Qualitative research focuses on understanding attitudes, behaviors, and motivations through open-ended questions and observati...read more

Database type refers to the structure and organization of data within a database system.

• Database types include relational, NoSQL, object-oriented, and hierarchical databases.

• Relational databases store data in tables with rows and columns, using SQL for querying.

• NoSQL databases are non-relational and can store unstructured data, such as MongoDB or Cassandra.

• Object-oriented databases store data as objects, with attributes and methods.

• Hierarchical databases organize data in a tr...read more

Go Lang supports various design patterns like Singleton, Factory, Observer, etc.

• Singleton pattern ensures a class has only one instance and provides a global point of access. Example: sync.Once in Go.

• Factory pattern creates objects without specifying the exact class to create. Example: encoding/json package in Go.

• Observer pattern defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated. Example: channe...read more

git grep is a command in Git that allows you to search through the contents of files in a Git repository.

• Allows searching through the contents of files in a Git repository

• Similar to the 'grep' command in Unix/Linux

• Can be used to search for specific strings or patterns in files

• Useful for finding references to functions, variables, or text within the codebase

Profilers are tools used to analyze the performance of software applications by measuring various metrics such as CPU usage, memory usage, and execution time.

• Profilers help identify bottlenecks and optimize code for better performance.

• Examples of profilers include VisualVM, YourKit, and Xcode Instruments.

• Profiling can be done for different aspects of an application, such as CPU profiling, memory profiling, and network profiling.

There are approximately 20% of cars in Delhi that are red.

• Delhi has a high population density and traffic congestion, leading to a higher number of cars on the road.

• Red is a popular color choice for cars in India, especially for luxury and sports cars.

• Based on national statistics, around 20% of cars in India are red, so a similar percentage can be assumed for Delhi.

A recursive function is a function that calls itself within its definition.

• A recursive function must have a base case to prevent infinite recursion.

• Recursion can be used to solve problems that can be broken down into smaller, similar subproblems.

• Example: Factorial calculation using recursion: def factorial(n): return 1 if n == 0 else n * factorial(n-1)

The diameter of a circle is a straight line passing through the center of the circle and connecting two points on the circumference.

• The diameter is always twice the length of the radius of the circle.

• The formula to calculate the diameter of a circle is: diameter = 2 * radius

• For example, if the radius of a circle is 5 cm, the diameter would be 10 cm.

The radius of a circle is the distance from the center of the circle to any point on its circumference.

• The radius is half the diameter of the circle.

• It is a constant distance from the center to any point on the circle.

• The formula to calculate the circumference of a circle using the radius is 2 * pi * radius.

• The formula to calculate the area of a circle using the radius is pi * radius^2.