10+ Dream11 Interview Questions and Answers

Find most common ancestor nodes of a binary tree given two integers.

• Traverse the tree to find the nodes with the given integers

• Store the path from root to each node in separate arrays

• Compare the two arrays to find the most common ancestor node

• If there are multiple common ancestors, return the one closest to the root

Find largest subarray with equal number of 1s and 0s

• Use a hashmap to store the count of 1s and 0s encountered so far

• If the count of 1s and 0s is equal at any point, calculate the length of subarray

• Keep track of the maximum length subarray found so far

Different types of testing in STLC lifecycle include unit testing, integration testing, system testing, and acceptance testing.

• Unit testing: Testing individual units or components of a software application.

• Integration testing: Testing the integration of different modules or components.

• System testing: Testing the entire system as a whole.

• Acceptance testing: Testing to ensure the system meets the requirements and is ready for deployment.

Building Amazon requires a multi-faceted approach involving technology, logistics, and customer-centricity.

• Develop a robust e-commerce platform with a user-friendly interface

• Establish a vast network of warehouses and distribution centers for efficient delivery

• Invest in cutting-edge technology such as AI and machine learning for personalized recommendations

• Prioritize customer satisfaction through excellent customer service and easy returns

• Partner with third-party sellers to ex...read more

The best days to buy and sell stocks depend on market trends and individual stock performance.

• Monitor market trends and stock performance

• Consider buying during market dips and selling during market highs

• Research historical data and patterns

• Consult with financial advisors

• Be mindful of taxes and fees

Estimate the number of users on the application based on market research, user demographics, and industry trends.

• Consider the total addressable market (TAM) for the application

• Analyze user demographics and behavior to estimate adoption rate

• Look at industry benchmarks and competitor data for reference

• Use surveys, focus groups, and user feedback to gather insights

• Consider factors like market saturation, growth potential, and user retention rates

MYSQL window functions allow for calculations across rows in a result set.

• Window functions are used to perform calculations across rows in a result set

• They are used with the OVER() clause

• Examples include ROW_NUMBER(), RANK(), DENSE_RANK(), and NTILE()

• They can be used to calculate running totals, moving averages, and more

Recommendation system uses data analysis and machine learning algorithms to suggest items to users based on their preferences.

• Collect user data and item data

• Analyze data to find patterns and similarities

• Use machine learning algorithms to make predictions and suggest items to users

• Continuously update and improve the system based on user feedback

• Examples: Netflix suggesting movies based on viewing history, Amazon suggesting products based on purchase history

Find quadraplets in an array that sum up to a target value.

• Use a nested loop to iterate through all possible combinations of quadraplets.

• Keep track of the sum of each quadraplet and compare it to the target value.

• Return the quadraplets that match the target sum.

Find the Nth greatest element in an array without sorting

• Use a priority queue to keep track of the N greatest elements

• Iterate through the array and add elements to the priority queue

• Return the top element from the priority queue as the Nth greatest element

Heater Problem - Find minimum radius to cover all houses with heaters

• Sort the houses and heaters arrays

• For each house, find the closest heater using binary search

• Calculate the minimum radius needed to cover all houses

The LLD of the current project involves detailed design of the system architecture and components.

• LLD includes detailed design of modules, classes, interfaces, and relationships between components.

• It focuses on how the system will be implemented based on the requirements specified in the HLD.

• LLD helps in understanding the flow of data and control within the system.

• It also includes design patterns, algorithms, and data structures to be used in the implementation.

• Example: In a ...read more