数据结构120-实现容量恒为质数代码-阿里云开发者社区

数据结构120-实现容量恒为质数代码

2023-02-11 35

版权

本文内容由阿里云实名注册用户自发贡献，版权归原作者所有，阿里云开发者社区不拥有其著作权，亦不承担相应法律责任。具体规则请查看《阿里云开发者社区用户服务协议》和《阿里云开发者社区知识产权保护指引》。如果您发现本社区中有涉嫌抄袭的内容，填写侵权投诉表单进行举报，一经查实，本社区将立刻删除涉嫌侵权内容。

简介： 数据结构120-实现容量恒为质数代码

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>哈希表的封装</title>
  </head>
  <body>
    <script>
      function hashFunc(str, size) {
        var hashCode = 0;
        //霍纳算法
        for (var i = 0; i < str.length; i++) {
          hashCode = 37 * hashCode + str.charCodeAt(i);
        }
        var index = hashCode % size;
        return index;
      }
      function HashTable() {
        this.storage = [];
        this.count = 0;
        this.limit = 7 * 2;
        //方法
        HashTable.prototype.put = function (key, value) {
          //根据key获取对应的index
          var index = this.hashFunc(key, this.limit);
          //根据index取出对应的bucket
          var bucket = this.storage[index];
          //、
          if (bucket == null) {
            (bucket = []), (this.storage[index] = bucket);
          }
          for (var i = 0; i < bucket.length; i++) {
            var tuple = bucket[i];
            if (tuple[0] == key) {
              tuple[1] = value;
              return;
            }
          }
          bucket.push([key, value]);
          this.count += 1;
          //判断是否需要扩容
          if (this.count > this.limit * 0.75) {
            var newSize=this.limit*2
            var newPrime=this.getPrime(newSize)
            this.resize(newPrime);
          }
        };
        HashTable.prototype.get = function (key) {
          //
          var index = this.hashFunc(key, this.limit);
          //根据index取出对应的bucket
          var bucket = this.storage[index];
          if (bucket == null) {
            return null;
          }
          for (var i = 0; i < bucket.length; i++) {
            var tuple = bucket[i];
            if (tuple[0] == key) {
              return tuple[1];
            }
          }
          return null;
        };
        HashTable.prototype.remove = function (key) {
          var index = this.hashFunc(key, this.limit);
          //根据index取出对应的bucket
          var bucket = this.storage[index];
          if (bucket == null) {
            return null;
          }
          for (var i = 0; i < bucket.length; i++) {
            var tuple = bucket[i];
            if (tuple[0] == key) {
              bucket.splice(i, 1);
              this.count--;
              return tuple[1];
              if (this.limit > 7 && this.count < this.limit * 0.25) {
                this.resize(Math.floor(this.limit / 2));
              }
            }
          }
          return null;
        };
        HashTable.prototype.isEmpty = function (key) {
          return this.count == 0;
        };
        HashTable.prototype.size = function (key) {
          return this.count;
        };
        HashTable.prototype.resize = function (key) {
          var oldStorage = this.storage;
          //重置所有的属性
          this.storage = [];
          this.count = 0;
          this.limit = newLimit;
          for (var i = 0; i < bucket.length; i++) {
            var bucket = oldStorage[i];
            if (bucket == null) {
              continue;
            }
            for (var j = 0; j < bucket.length; j++) {
              var tuple = bucket[j];
              this.put(tuple[0], tuple[1]);
            }
          }
        };
        HashTable.prototype.isPrime = function (num) {
          var temp = parseInt(Math.sqrt(num));
          for (var i = 2; i <= temp; i++) {
            if (num % i == 0) {
              return false;
            }
          }
          return true;
        };
        HashTable.prototype.getPrime = function (num) {
            while(!this.isPrime(num)){
                num++
            }
            return num
        }
      }
    </script>
  </body>
</html>

数据结构120-实现容量恒为质数代码

热门文章

最新文章

相关课程

相关电子书