Walmart Labs Interview Questions, Process, and Tips

A graph data structure can be used to solve a Rubix cube.

• Each cubelet can be represented as a node in the graph.

• Edges can be added between nodes to represent possible moves.

• A search algorithm like BFS or DFS can be used to find the solution.

Dynamic programming solution to find if a given weight can be formed using an array of weights

• Create a boolean array of size (given weight + 1) to store if a weight can be formed or not

• Initialize the first element of the boolean array to true

• Iterate through the array of weights and for each weight, iterate through the boolean array and mark true for all weights that can be formed using the current weight

• Return the valu...read more

Stack data structure is suitable for implementing Redo and Undo operations.

• Stack follows Last-In-First-Out (LIFO) order, which is ideal for undoing and redoing operations.

• When an operation is performed, it can be pushed onto the stack for undoing later.

• To redo an operation, the previously undone operations can be popped from the stack.

• Stack provides efficient insertion and deletion at one end, making it suitable for un

A router is a networking device that forwards data packets between computer networks.

• Routers operate at the network layer of the OSI model.

• They use routing tables to determine the best path for data packets to travel.

• Routers can connect multiple networks together, such as a home network to the internet.

• They can also provide security by blocking unauthorized access to a network.

• Examples of routers include Cisco, Netgear

Developed a web-based project management tool for a client

• Used React.js for the frontend and Node.js for the backend

• Implemented user authentication and authorization using JWT

• Integrated with third-party APIs such as Google Drive and Trello

• Implemented real-time notifications using WebSockets

• Deployed the application on AWS EC2 instance

The internet is a global network of interconnected devices that communicate with each other using standardized protocols.

• The internet is made up of millions of interconnected devices such as computers, servers, routers, and switches.

• Data is transmitted across the internet using standardized protocols such as TCP/IP.

• The internet is accessed through Internet Service Providers (ISPs) who provide users with a connection to...read more

Finding number of paths in tree with sum of node values equal to count using recursion.

• Use recursion to traverse the tree and keep track of the sum of node values.

• At each node, check if the current sum equals the desired count.

• If yes, increment the path count.

• Recursively traverse the left and right subtrees.

• Return the total path count.

• Example: Given a tree with values [10, 5, -3, 3, 2, null, 11], count the number of pa...read more

The question is about finding the intersection point of two linked lists.

• Traverse both linked lists and find their lengths

• Move the pointer of the longer list ahead by the difference in lengths

• Now, traverse both lists simultaneously until the pointers meet, which will be the intersection point

JVM is platform independent because it uses bytecode and provides a runtime environment for executing Java programs.

• JVM stands for Java Virtual Machine.

• It executes Java bytecode, which is a platform-independent intermediate representation of the Java program.

• JVM provides a runtime environment that abstracts the underlying hardware and operating system.

• The bytecode is compiled once and can run on any system with a compa...read more

Java and C++ are both object-oriented programming languages, but they have differences in syntax, memory management, and platform compatibility.

• Java is platform-independent, while C++ is platform-dependent.

• Java uses automatic memory management (garbage collection), while C++ requires manual memory management.

• Java has a simpler syntax and is easier to learn, while C++ has a more complex syntax and is considered more dif...read more

A code for building a heap and its time complexity

• A heap is a complete binary tree where each node is greater than or equal to its children

• To build a heap, start from the last non-leaf node and heapify down each node

• Time complexity: O(n) for building a heap of n elements

Find the k largest elements in an array.

• Sort the array in descending order.

• Return the first k elements of the sorted array.

• If k is larger than the array size, return the entire array.