GigIndia Interview Questions and Answers

Find the first non-repeating character in a string.

• Create a hash table to store the frequency of each character in the string.

• Iterate through the string and check the frequency of each character.

• Return the first character with a frequency of 1.

Connection pooling is a technique of reusing database connections to improve performance.

• Connection pooling helps to reduce the overhead of creating and destroying database connections.

• It maintains a pool of connections that can be reused by multiple clients.

• Connection pooling is commonly used in web applications to handle multiple requests simultaneously.

• It can be configured with parameters like maximum number of conn...read more

A singleton class in PHP is a class that can only be instantiated once.

• Create a private constructor to prevent direct instantiation

• Create a private static variable to hold the instance of the class

• Create a public static method to get the instance of the class

• Ensure that the public static method always returns the same instance

To connect to MySQL database using PHP, create a Connection class.

• Use mysqli_connect() function to establish a connection

• Pass the database credentials as parameters to the function

• Create a constructor method to initialize the connection

• Create a query method to execute SQL queries

• Close the connection using mysqli_close() method

There are three types of errors in PHP: syntax errors, runtime errors, and logical errors.

• Syntax errors occur when the code is not written correctly, such as missing semicolons or parentheses.

• Runtime errors occur during the execution of the code, such as trying to access an undefined variable.

• Logical errors occur when the code runs without errors, but produces unexpected results, such as a miscalculation in a formula.

Session in PHP allows to store user data on the server for later use.

• Session starts when a user logs in and ends when the user logs out or the session expires.

• Session data is stored on the server and identified by a unique session ID.

• Session variables can be set and accessed using the $_SESSION superglobal array.

• Session can be destroyed using the session_destroy() function.

• Session can be used to store user-specific dat...read more

Find missing element in an array of elements from 0 to n-1

• Calculate sum of all elements in array and subtract from sum of n natural numbers

• Use XOR operation on all elements and n natural numbers

• Sort the array and find the missing element

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

I got to participate in a robotics competition at IIT

• Designed and built a robot from scratch

• Programmed the robot to complete tasks autonomously

• Competed against other teams from different colleges

• Learned valuable skills in engineering and teamwork

I chose IIT for its reputation and opportunities. No regrets. The environment is competitive and challenging.

• IIT has a strong reputation for producing successful graduates

• I was attracted to the opportunities for research and innovation

• The academic environment is highly competitive and challenging

• I have no regrets about my decision to attend IIT

A portfolio is a collection of investments. Risk can be measured through standard deviation, beta, or value at risk.

• A portfolio is a combination of different investments such as stocks, bonds, and mutual funds.

• The purpose of a portfolio is to diversify investments and reduce risk.

• Risk can be measured through standard deviation, which measures the volatility of returns.

• Beta measures the sensitivity of a portfolio to mar...read more

Beta is a measure of a stock's volatility. Value at risk is a statistical measure of potential losses. Formula for beta is Covariance(Stock, Market) / Variance(Market).

• Beta measures a stock's sensitivity to market movements.

• Value at risk is the maximum potential loss that an investment portfolio may suffer within a given time frame.

• Beta formula is calculated by dividing the covariance of the stock and market returns by...read more

Covariance measures the relationship between two variables. It measures sensitivity by indicating the direction of the relationship.

• Covariance is a statistical measure that shows how two variables are related to each other.

• It measures the direction of the relationship between two variables.

• A positive covariance indicates that the two variables move in the same direction.

• A negative covariance indicates that the two vari...read more

WACC is the weighted average cost of capital. To value a company, one can use various methods such as DCF, comparables, or precedent transactions. A method to decide on project undertaking is NPV analysis.

• WACC is the average cost of all the capital a company has raised

• To value a company, one can use DCF, comparables, or precedent transactions

• DCF involves projecting future cash flows and discounting them back to present...read more

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