LeetCode 705. Design HashSet (设计哈希集合)

题目标签：HashMap

　　题目让我们设计一个 hashset，有add，contains，remove 功能。

　　建立一个boolean array，index 是数字的值，具体看code。

Java Solution:

Runtime: 58 ms, faster than 90.21% 

Memory Usage: 56.3 MB, less than 68.53%

完成日期：03/18/2019

关键点：boolean array

class MyHashSet {
    boolean [] set;
    /** Initialize your data structure here. */
    public MyHashSet() {
        set = new boolean[1000001];
    }
    
    public void add(int key) {
        set[key] = true;
    }
    
    public void remove(int key) {
        set[key] = false;
    }
    
    /** Returns true if this set contains the specified element */
    public boolean contains(int key) {
        return set[key];
    }
}

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

参考资料：N/A

LeetCode 题目列表 - LeetCode Questions List

题目来源：https://leetcode.com/