index.js

// Design a HashSet without using any built -in hash table libraries.
// To be specific, your design should include these functions:

// add(value): Insert a value into the HashSet.
// contains(value) : Return whether the value exists in the HashSet or not.
// remove(value): Remove a value in the HashSet.If the value does not exist in the HashSet, do nothing.

// Example:

// MyHashSet hashSet = new MyHashSet();
// hashSet.add(1);
// hashSet.add(2);
// hashSet.contains(1);    // returns true
// hashSet.contains(3);    // returns false (not found)
// hashSet.add(2);
// hashSet.contains(2);    // returns true
// hashSet.remove(2);
// hashSet.contains(2);    // returns false (already removed)

// Note:

// All values will be in the range of[0, 1000000].
// The number of operations will be in the range of[1, 10000].
// Please do not use the built -in HashSet library.

// Solution

class MyHashSet {
  constructor() {
    this.hashSet = new Set();
  }
}

MyHashSet.prototype.add = function (key) {
  this.hashSet.add(key);
};

MyHashSet.prototype.remove = function (key) {
  this.hashSet.delete(key);
};

MyHashSet.prototype.contains = function (key) {
  return this.hashSet.has(key);
};