import random


class RandomizedSet:

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.d = {}

    def insert(self, val: int) -> bool:
        """
        Inserts a value to the set. Returns true if the set did not already contain the specified element.
        """
        if self.d.get(val):
            return False
        else:
            self.d[val] = True
            return True

    def remove(self, val: int) -> bool:
        """
        Removes a value from the set. Returns true if the set contained the specified element.
        """
        if self.d.get(val):
            del self.d[val]
            return True
        else:
            return False

    def getRandom(self) -> int:
        """
        Get a random element from the set.
        """
        return random.choice(list(self.d.keys()))

# Your RandomizedSet object will be instantiated and called as such:
# obj = RandomizedSet()
# param_1 = obj.insert(val)
# param_2 = obj.remove(val)
# param_3 = obj.getRandom()

# Time Complexity: O(1)
# Space Complexity: O(n) for n maximum number of elements at any given point

# Runtime: 396 ms, faster than 33.29% of Python3 online submissions for Insert Delete GetRandom O(1).
# Memory Usage: 17.9 MB, less than 54.54% of Python3 online submissions for Insert Delete GetRandom O(1).