Design HashSet

Description

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(javascript)

/**
 * Initialize your data structure here.
 */
var MyHashSet = function() {
    this.hashset = new Set();
};

/** 
 * @param {number} key
 * @return {void}
 */
MyHashSet.prototype.add = function(key) {
    this.hashset.add(key);
};

/** 
 * @param {number} key
 * @return {void}
 */
MyHashSet.prototype.remove = function(key) {
    this.hashset.delete(key);
};

/**
 * Returns true if this set contains the specified element 
 * @param {number} key
 * @return {boolean}
 */
MyHashSet.prototype.contains = function(key) {
    return this.hashset.has(key);
};

/** 
 * Your MyHashSet object will be instantiated and called as such:
 * var obj = new MyHashSet()
 * obj.add(key)
 * obj.remove(key)
 * var param_3 = obj.contains(key)
 */