Find the k most frequent elements in a given array of numbers. Return the top k elements based on their frequency.

Implement a Tic-Tac-Toe game where players take turns placing their marks. Design the game logic to efficiently determine the winner after each move.

Design a data structure that acts as a Least Recently Used (LRU) cache. Implement methods to get and put key-value pairs, evicting the least recently used entry when the cache is full.