Class 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