OOP Concepts: Encapsulation: Wrapping data and methods into a class to protect and restrict access. Inheritance: Reusing properties and methods of a parent class in a child class. Polymorphism: The ability to take multiple forms, like method overriding or overloading. Abstraction: Hiding implementation details and exposing only essential features. Classes and Objects: Classes are blueprints; objects are instances of these classes. DSA Questions: Reverse a linked list. Find the maximum subarray sum using Kadane's algorithm. Implement binary search in a sorted array. Detect a cycle in a graph (DFS/BFS). Sort an array using quicksort or mergesort.