Revolut Backend Developer Interview Questions and Answers

TreeSet is a data structure that stores unique elements in sorted order.

• TreeSet is implemented using a Red-Black tree

• It provides O(log n) time complexity for basic operations like add, remove, and contains

• It also provides methods like first(), last(), headSet(), tailSet(), and subSet()

• TreeSet can be used to implement priority queues and sorting algorithms

Design an ArrayList with getMax functionality.

• Create a custom ArrayList class that extends the existing ArrayList class.

• Add a getMax() method that returns the maximum value in the list.

• Override the add() method to keep track of the maximum value in the list.

• Update the maximum value whenever an element is added or removed from the list.

To find a loop in a linked list, we use Floyd's cycle-finding algorithm.

• Floyd's cycle-finding algorithm uses two pointers, one moving at a rate of one node per iteration and the other moving at a rate of two nodes per iteration.

• If there is a loop in the linked list, the two pointers will eventually meet at some node.

• To find the starting point of the loop, we reset one of the pointers to the head of the linked list and ...read more

Discussing project applications in PayPal and basic ML concepts for data analysis.

• Utilizing customer transaction data to identify spending patterns and improve personalized marketing strategies.

• Implementing machine learning algorithms to detect fraudulent transactions in real-time, enhancing security.

• Analyzing user behavior on the PayPal platform to optimize user experience and streamline the payment process.

• Using pred...read more