LRU Cache

Design a data structure that follows the constraints of a **Least Recently Used (LRU) cache**. Implement the `LRUCache` class: - `LRUCache(int capacity)` Initialize the LRU cache with **positive** size `capacity`. - `int get(int key)` Return the value of the `key` if the key exists, otherwise return `-1`. - `void put(int key, int value)` Update the value of the `key` if the `key` exists. Otherwise, add the `key-value` pair to the cache. If the number of keys exceeds the `capacity` from this operation, **evict** the least recently used key. The functions `get` and `put` must each run in O(1) average time complexity. **Note:** For this problem, implement operations as a function that takes the capacity and a list of operations.