705. Design HashSet

题目描述

leetcode-cn.com/problems/de…

分析

将在上一题基础上修改 juejin.cn/post/706675…

算法

哈希

过程

基本与集合一样，只是多了 value 的事情

因此在存储时候，应该存的是一个 tuple: [key, value]

代码

var MyHashSet = function() {
    this.base = 769
    this.data = new Array(this.base).fill(0).map(() => new Array())
};

/** 
 * @param {number} key
 * @return {void}
 */
MyHashSet.prototype.add = function(key) {
    if (this.contains(key)) return
    const ind = this.hash(key)
    this.data[ind].push(key)
};

/** 
 * @param {number} key
 * @return {void}
 */
MyHashSet.prototype.remove = function (key) {
        const h = this.hash(key)
        const it = this.data[h]
        for (let i = 0; i < it.length; ++i) {
          if (it[i] === key) {
            it.splice(i, 1)
            return
          }
        }
      }

/** 
 * @param {number} key
 * @return {boolean}
 */
MyHashSet.prototype.contains = function(key) {
    const ind = this.hash(key)
    for (const x of this.data[ind]) {
        if (x === key) return true
    }
    
    return false
};

/** 
 * @param {number} key
 * @return {number}
 */
MyHashSet.prototype.hash = function(key) {
    return key % this.base
};

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