"""Leetcode 380. Insert Delete GetRandom O(1)
Medium

URL: https://leetcode.com/problems/insert-delete-getrandom-o1/

Design a data structure that supports all following operations in average O(1)
time.
- insert(val): Inserts an item val to the set if not already present.
- remove(val): Removes an item val from the set if present.
- getRandom: Returns a random element from current set of elements. Each element
must have the same probability of being returned.

Example:
// Init an empty set.
RandomizedSet randomSet = new RandomizedSet();

// Inserts 1 to the set. Returns true as 1 was inserted successfully.
randomSet.insert(1);

// Returns false as 2 does not exist in the set.
randomSet.remove(2);

// Inserts 2 to the set, returns true. Set now contains [1,2].
randomSet.insert(2);

// getRandom should return either 1 or 2 randomly.
randomSet.getRandom();

// Removes 1 from the set, returns true. Set now contains [2].
randomSet.remove(1);

// 2 was already in the set, so return false.
randomSet.insert(2);

// Since 2 is the only number in the set, getRandom always return 2.
randomSet.getRandom();

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()
"""

class RandomizedSet(object):

    def __init__(self):
        """
        Initialize your data structure here.
        """
        pass

    def insert(self, val):
        """
        Inserts a value to the set. Returns true if the set did not already contain the specified element.
        :type val: int
        :rtype: bool
        """
        pass

    def remove(self, val):
        """
        Removes a value from the set. Returns true if the set contained the specified element.
        :type val: int
        :rtype: bool
        """
        pass

    def getRandom(self):
        """
        Get a random element from the set.
        :rtype: int
        """
        pass


def main():
    pass


if __name__ == '__main__':
    main()

Add lc0380_insert_delete_getrandom_o1.py