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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:

• 0 <= key <= 106
• At most 104 calls will be made to add, remove, and contains.

 

Follow up: Could you solve the problem without using the built-in HashSet library?

Related Topics

[Design] [Hash Table]

Similar Questions

1. Design HashMap (Easy)

Documentation

Index

• type MyHashSet
  • func Constructor() MyHashSet
  • func (this *MyHashSet) Add(key int)
  • func (this *MyHashSet) Contains(key int) bool
  • func (this *MyHashSet) Remove(key int)

Types

type MyHashSet

type MyHashSet struct {
	// contains filtered or unexported fields
}

func Constructor

func Constructor() MyHashSet

* Initialize your data structure here.

func (*MyHashSet) Add

func (this *MyHashSet) Add(key int)

func (*MyHashSet) Contains

func (this *MyHashSet) Contains(key int) bool

* Returns true if this set contains the specified element

func (*MyHashSet) Remove

func (this *MyHashSet) Remove(key int)