Insert Delete GetRandom O(1)

Implement RandomizedSet supporting average O(1) time operations: insert(val) -> bool: Insert val if not present and return True; otherwise return False. remove(val) -> bool: Remove val if present and return True; otherwise return False. getRandom() -> int: Return a random element from the set with equal probability. The set is guaranteed non-empty when called. Constraints: number of operations 1 <= ops <= 2*10^5, values are 32-bit integers. Example Input insert(1) remove(2) insert(2) getRandom() Output True False True (returns 1 or 2)