100+ Performance.io Interview Questions and Answers

I'll sell you my ballpen, it writes smoothly and has a comfortable grip.

• This ballpen writes smoothly and effortlessly

• It has a comfortable grip that makes writing easy

• The ink is long-lasting and doesn't smudge

• It's perfect for everyday use, whether at home, school, or work

Vertical sum of binary tree is the sum of all nodes in each vertical line of the tree.

• Traverse the tree in-order and keep track of the horizontal distance of each node from the root.

• Use a hash table to store the sum of nodes at each horizontal distance.

• Recursively traverse the left and right subtrees and update the hash table accordingly.

Find the maximum product of three numbers in an array.

• Sort the array in ascending order.

• Multiply the last three numbers in the sorted array to get the maximum product.

• If there are negative numbers in the array, consider multiplying the two smallest negative numbers with the largest positive number.

I can help increase revenue for SD by identifying new business opportunities, building strong relationships with clients, and implementing effective sales strategies.

• Identifying new business opportunities through market research and analysis

• Building strong relationships with clients through effective communication and customer service

• Implementing effective sales strategies such as cross-selling and upselling

• Collaborating with marketing and product teams to develop targeted ca...read more

Loop detection in a linked list.

• Use two pointers, one moving at twice the speed of the other.

• If there is a loop, the faster pointer will eventually catch up to the slower one.

• If there is no loop, the faster pointer will reach the end of the list.

Defective ball puzzle involves finding the odd ball out of a group of identical balls using a balance scale.

• Divide the balls into groups and weigh them on the balance scale.

• If the scale tips, the odd ball is in the heavier group.

• If the scale doesn't tip, the odd ball is in the remaining group.

• Repeat the process until the odd ball is found.

• Example: 8 identical balls, one is heavier. Divide into groups of 3 and weigh. If the scale tips, weigh two of the three balls to find the ...read more

Reverse a linked list in chunks of k nodes

• Break the linked list into chunks of size k

• Reverse each chunk individually

• Connect the reversed chunks back together

Vector is synchronized and ArrayList is not. Vector is thread-safe and ArrayList is not.

• Vector is a legacy class and ArrayList is a part of the Java Collection Framework.

• Vector is synchronized which means only one thread can access it at a time, while ArrayList is not.

• Vector is thread-safe which means it can be used in a multi-threaded environment, while ArrayList is not.

• Vector is slower than ArrayList because of synchronization.

• Vector increases its size by 100% while ArrayLi...read more

The number of sparrows in IIT KGP is unknown.

• The exact number of sparrows in IIT KGP is not available.

• There is no specific data on the population of sparrows in IIT KGP.

• The number of sparrows in IIT KGP is not documented.

• No information is available regarding the count of sparrows in IIT KGP.

Group by is used to group rows that have the same values into summary rows. Having is used to filter groups based on a specified condition.

• Group by is used with aggregate functions like COUNT, SUM, AVG, etc.

• Having is used to filter groups based on conditions after the grouping has been done.

• Example: SELECT department, COUNT(*) FROM employees GROUP BY department HAVING COUNT(*) > 5;

The diameter of a binary tree is the number of nodes on the longest path between two leaves in the tree.

• The diameter of a binary tree can be calculated by finding the longest path between two nodes in the tree.

• It is not necessarily the same as the height of the tree.

• The diameter can be found by calculating the sum of the heights of the left and right subtrees of each node.

An immutable class is a class whose instances cannot be modified after creation.

• Make all fields private and final

• Don't provide any setter methods

• Ensure that any mutable objects passed to the constructor are defensively copied

• Make the class final so that it cannot be subclassed

Online shopping is the process of purchasing goods or services over the internet.

• Online shopping allows customers to browse and buy products from the comfort of their own homes.

• It offers convenience, as customers can shop anytime and anywhere.

• Customers have access to a wide variety of products and can compare prices easily.

• Online shopping eliminates the need to physically visit stores, saving time and effort.

• Examples of popular online shopping platforms include Amazon, eBay, ...read more

Left view of a tree shows the nodes visible when viewed from the left side.

• Left view of a tree is the nodes that are visible when looking at the tree from the left side.

• It includes the leftmost node at each level of the tree.

• Example: For a tree with root node A and left child B, the left view would be [A, B].

The Lowest Common Ancestor (LCA) of a binary tree can be found in place using a recursive approach.

• Start from the root node and recursively check if both nodes are present in the left and right subtrees.

• If one node is found in the left subtree and the other in the right subtree, then the current node is the LCA.

• If both nodes are found in the left subtree, recursively search for the LCA in the left subtree.

• If both nodes are found in the right subtree, recursively search for th...read more

Snapdeal is a leading e-commerce platform in India, offering a wide range of products and services.

• Snapdeal has a vast product catalog, providing customers with a wide variety of options.

• The platform offers competitive prices and frequent discounts, making it attractive for customers.

• Snapdeal has a user-friendly interface and a seamless shopping experience.

• The company has a strong logistics network, ensuring timely delivery of products.

• Snapdeal has a robust customer support s...read more

Singleton pattern ensures only one instance of a class is created and provides a global point of access to it.

• Create a private constructor to prevent direct instantiation of the class.

• Create a private static instance of the class.

• Create a public static method to access the instance, and create the instance if it doesn't exist.

• Ensure thread safety by using synchronized keyword or double-checked locking.

The road length of Ahmedabad is approximately 2,500 kilometers.

• Ahmedabad has a well-developed road network.

• The road length includes both national highways and city roads.

• The road length is constantly expanding due to urban development and infrastructure projects.

• Major roads in Ahmedabad include the SG Highway, Ashram Road, and C.G. Road.

Find the pair element from the array

• Iterate through the array and use a hashmap to store elements and their counts

• Check if the current element's complement exists in the hashmap

• Return the pair if found, otherwise return null

Knapsack and coin change problems are classic dynamic programming problems.

• Knapsack problem involves maximizing the value of items in a knapsack without exceeding its capacity.

• Coin change problem involves finding the minimum number of coins needed to make a certain amount of change.

• Both problems can be solved using dynamic programming techniques.

• Examples: 0/1 Knapsack, Fractional Knapsack, Coin Change with limited coins.

Intersection of 2 linked lists

• Traverse both lists and compare each node to find the intersection

• Use a hash set to store visited nodes and check for intersection

• Calculate the length of both lists and adjust the starting point for comparison

Printing the left view of a tree involves printing the leftmost nodes at each level of the tree.

• Traverse the tree level by level using BFS or DFS

• At each level, print the first node encountered

• Continue this process until all levels are covered

The coin change problem in dynamic programming involves finding the minimum number of coins needed to make a certain amount of change.

• Start by defining the problem - given a set of coin denominations and a target amount, find the minimum number of coins needed to make the target amount.

• Use dynamic programming to build up solutions for smaller subproblems and eventually solve the main problem.

• Consider the base case where the target amount is 0, the minimum number of coins need...read more

The boundary of a tree refers to the outermost edges of the tree canopy or the perimeter of the tree's root system.

• The boundary of a tree is defined by the outermost branches and leaves of the tree canopy.

• The root system of a tree also contributes to its boundary, with roots extending outward from the trunk.

• The boundary of a tree can be influenced by factors such as soil type, available nutrients, and competition from other plants.

• Examples: Oak tree with a wide canopy, Pine t...read more

The company follows a systematic working process to ensure efficient operations.

• The company has defined workflows and procedures for each department.

• Tasks are assigned to employees based on their skills and expertise.

• There is a clear hierarchy and reporting structure in place.

• Regular communication and collaboration among team members.

• The company may use software or tools to streamline data entry processes.

• Quality checks and audits are conducted to ensure accuracy and complian...read more

Convert Roman numerals to integers using a mapping of values for each symbol.

• Create a mapping of Roman numeral symbols to their corresponding integer values.

• Iterate through the input Roman numeral string from right to left.

• If the current symbol's value is less than the next symbol's value, subtract it from the total. Otherwise, add it to the total.

The order of execution refers to the sequence in which instructions or operations are executed in a program.

• The order of execution is determined by the programming language and the specific code being executed.

• Generally, code is executed line by line from top to bottom.

• However, there are exceptions such as loops, conditionals, and function calls that can alter the order of execution.

• In some programming languages, there are also concepts like multithreading or asynchronous exe...read more