MyHashSet

All Implemented Interfaces:
```
public final class MyHashSet

                    
```
705 - Design HashSet\.
Easy
Design a HashSet without using any built-in hash table libraries.
Implement MyHashSet class:
- 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:
- <code>0 <= key <= 10<sup>6</sup></code>
- At most <code>10<sup>4</sup></code> calls will be made to add, remove, and contains.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description

Field Summary

Fields
Modifier and Type	Field	Description

Constructor Summary

Constructors
Constructor	Description
`MyHashSet()`

Enum Constant Summary

Enum Constants
Enum Constant	Description

Method Summary

Modifier and Type	Method	Description
`final Unit`	`add(Integer key)`
`final Unit`	`remove(Integer key)`
`final Boolean`	`contains(Integer key)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- MyHashSet
```
MyHashSet()
```

Method Detail

add
```
 final Unit add(Integer key)
```

remove
```
 final Unit remove(Integer key)
```

contains
```
 final Boolean contains(Integer key)
```