Design a HashSet

Easy
5
42.2% Acceptance

Design and implement a HashSet without using any built-in hash table libraries in JavaScript. The main focus of this lab is to evaluate your understanding of hash table concepts and problem-solving skills.

A HashSet is a collection of unique elements. It supports add, remove, and contains operations. Your task is to implement the MyHashSet class with the following methods:

  • void add(key) Inserts the value key into the HashSet.
  • bool contains(key) Returns whether the value key exists in the HashSet or not.
  • void remove(key) Removes the value key in the HashSet. If key does not exist in the HashSet, do nothing.

Example 1

Input

["MyHashSet", "add", "add", "contains", "contains", "add", "contains", "remove", "contains"]
[[], [1], [2], [1], [3], [2], [2], [2], [2]]

Output

[null, null, null, true, false, null, true, null, false]

Explanation

MyHashSet myHashSet = new MyHashSet();
myHashSet.add(1);      // set = [1]
myHashSet.add(2);      // set = [1, 2]
myHashSet.contains(1); // return True
myHashSet.contains(3); // return False, (not found)
myHashSet.add(2);      // set = [1, 2]
myHashSet.contains(2); // return True
myHashSet.remove(2);   // set = [1]
myHashSet.contains(2); // return False, (already removed)

Constraints

  • 0 <= key <= 10^6
  • At most 10^4 calls will be made to add, remove, and contains.

Examples

Example 2

myHashSet = new MyHashSet();
myHashSet.add(1);
myHashSet.add(2);
myHashSet.contains(1); // Expected output: true

Example 3

myHashSet = new MyHashSet();
myHashSet.add(1);
myHashSet.add(2);
myHashSet.contains(3); // Expected output: false

Example 4

myHashSet = new MyHashSet();
myHashSet.add(1);
myHashSet.add(2);
myHashSet.add(2);
myHashSet.contains(2); // Expected output: true

Challenges

  1. Implement the MyHashSet class using Arrays.
  2. Implement the MyHashSet class using Linked Lists.
  3. Implement the MyHashSet class using a dynamic size to avoid collisions.

In each challenge, export the required functions and variables to be used in the evaluation script.