0705. Design Hash Set

# 705. Design HashSet#

## 题目 #

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.contains(1);    // returns true
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.

## 题目大意 #

• contains(value) ：返回哈希集合中是否存在这个值。
• remove(value)：将给定值从哈希集合中删除。如果哈希集合中没有这个值，什么也不做。

• 所有的值都在 [1, 1000000] 的范围内。
• 操作的总数目在 [1, 10000] 范围内。
• 不要使用内建的哈希集合库。

## 解题思路 #

• 简单题，设计一个 hashset 的数据结构，要求有 `add(value)``contains(value)``remove(value)`，这 3 个方法。

## 代码 #

``````
package leetcode

type MyHashSet struct {
data []bool
}

/** Initialize your data structure here. */
func Constructor705() MyHashSet {
return MyHashSet{
data: make([]bool, 1000001),
}
}

func (this *MyHashSet) Add(key int) {
this.data[key] = true
}

func (this *MyHashSet) Remove(key int) {
this.data[key] = false
}

/** Returns true if this set contains the specified element */
func (this *MyHashSet) Contains(key int) bool {
return this.data[key]
}

/**
* Your MyHashSet object will be instantiated and called as such:
* obj := Constructor();