Junior Data Scientist

Oracle

Given an undirected graph, determine whether a Hamiltonian path exists. A Hamiltonian path is a path in an undirected or directed graph that visits each vertex exactly once. If a Hamiltonian path exists, return true; otherwise, return false. For example, consider the following graph represented by an adjacency list: { 0: [1, 2], 1: [0, 2, 3], 2: [0, 1, 4], 3: [1, 4], 4: [2, 3] } A Hamiltonian path in this graph is [0, 1, 2, 4, 3]. Therefore, your function should return true. Now consider the following graph: { 0: [1, 2], 1: [0, 2], 2: [0, 1] } It is not possible to visit all vertices exactly once in a path. Therefore, your function should return false. Your task is to implement a function that takes the number of vertices n and the adjacency list representation of the graph graph as input and returns a boolean value indicating whether a Hamiltonian path exists in the graph. The graph will contain n vertices labeled from 0 to n-1. Constraints: 1 <= n <= 10 The graph is undirected. There are no self-loops. There are no duplicate edges.

Oracle

Let's design a system for deleting all user data in a large-scale application. Consider the following requirements: Compliance: The system must adhere to data privacy regulations (e.g., GDPR, CCPA) regarding the right to be forgotten. This means all personal data must be permanently and irrevocably deleted. Data Scope: User data is distributed across various databases (e.g., relational, NoSQL), object storage, and potentially third-party services. Examples include: User profiles in a relational database (name, email, address). User-generated content (photos, videos) in object storage. User activity logs in a NoSQL database. User data cached in a Redis cluster. User accounts on integrated third-party services (e.g., payment processors, social media platforms). Performance: The deletion process should be efficient and not significantly impact the performance of other system operations. Consider the impact on databases and other services during peak hours. Consistency: The system must ensure data consistency. For example, if a user has dependencies on other data (e.g., a user is an administrator of a group), these dependencies must be handled correctly (e.g., reassigning ownership, deleting dependent data). Auditability: All deletion requests and actions must be logged for auditing and compliance purposes. The logs should record who requested the deletion, when it was requested, what data was deleted, and the outcome of the deletion process. Error Handling: The system should gracefully handle errors and retries. If a deletion fails in one component, it should be retried or rolled back appropriately, and alerts should be generated. Scalability: The system must be able to handle a large number of deletion requests concurrently. Data Minimization: Before initiating the deletion process, verify if data minimization techniques can be applied instead of complete deletion, such as anonymization or pseudonymization, especially for datasets needed for analytical purposes. Given these requirements, how would you design a system to handle user data deletion requests? Discuss the architecture, components, data flow, and any trade-offs you would consider.

Oracle

Describe a time you had to work with a difficult person. What was the situation?** For example, were you working on a team project with a classmate who wasn't pulling their weight? Or perhaps you had a colleague who was constantly negative and bringing down the morale of the team? Who was the difficult person, and what made them difficult?** Was it a personality clash? Did they have different work styles? Were they simply uncooperative or unwilling to compromise? Be specific about their behaviors and how they impacted you and the team. What actions did you take to address the situation?** Did you try to communicate with the person directly? Did you involve a supervisor or mediator? Did you try to find common ground or compromise on solutions? What was the outcome?** Were you able to resolve the conflict and improve the working relationship? If not, what were the consequences? What did you learn from the experience, and how would you handle a similar situation differently in the future?