Python short and clean 1-liners. Bit manipulation.
Code\npython\nclass MyHashSet:\n\n    def __init__(self):\n        self.state = 0 \n\n    def add(self, key: int) -> None:\n        self.state |= (1 << key)\n\n
# Code\n```python\nclass MyHashSet:\n\n    def __init__(self):\n        self.state = 0 \n\n    def add(self, key: int) -> None:\n        self.state |= (1 << key)\n\n    def remove(self, key: int) -> None:\n        self.state &= ~(1 << key)\n\n    def contains(self, key: int) -> bool:\n        return self.state & (1 << key)\n\n\n```
['Hash Table', 'Bit Manipulation', 'Design', 'Python', 'Python3']