Snobol4 语言 查找算法原理案例 布隆过滤器简介

Snobol4阿木 发布于 2025-05-28 4 次阅读

阿木博主一句话概括：布隆过滤器【1】在Snobol4【2】语言中的实现与原理分析

阿木博主为你简单介绍：
布隆过滤器是一种空间效率极高的概率型数据结构【3】，用于测试一个元素是否在一个集合中。本文将围绕Snobol4语言，探讨布隆过滤器的算法原理【4】，并通过代码实现展示其在Snobol4中的具体应用。

关键词：布隆过滤器；Snobol4；算法原理；数据结构

一、
布隆过滤器（Bloom Filter）是由布隆（Bloom）在1970年提出的一种数据结构。它能够告诉我们一个元素是否可能存在于一个集合中，但无法确定该元素是否真的存在于集合中。布隆过滤器在空间和时间效率上具有显著优势，广泛应用于缓存【5】、数据库【6】、网络【7】等领域。

Snobol4是一种高级编程语言，由Peter J. Landin【8】在1962年设计。它具有简洁、易读的特点，适合于教学和实验。本文将使用Snobol4语言实现布隆过滤器，并分析其算法原理。

二、布隆过滤器的原理
布隆过滤器由一个位数组【9】和一系列哈希函数【10】组成。位数组是一个足够大的位数组，每个位初始时都设置为0。哈希函数是一系列将元素映射到位数组索引【11】的函数。

1. 插入元素【12】
当插入一个元素时，布隆过滤器会使用多个哈希函数计算该元素的多个索引，并将这些索引对应的位数组位置设置为1。

2. 检查元素【13】
当检查一个元素是否存在于集合中时，布隆过滤器会使用相同的哈希函数计算该元素的多个索引。如果所有索引对应的位数组位置都是1，则认为该元素可能存在于集合中；如果任何一个索引对应的位数组位置是0，则认为该元素一定不存在于集合中。

三、Snobol4语言实现布隆过滤器
以下是一个使用Snobol4语言实现的简单布隆过滤器示例：

```snobol
:BF
1000 !BF_SIZE
0 !BF_COUNT
0 !BF_HASH1
0 !BF_HASH2
0 !BF_HASH3

:INSERT
0 !BF_COUNT
1 !BF_HASH1
2 !BF_HASH2
3 !BF_HASH3
0 DO
1 + !BF_COUNT
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
0 UNTIL
1000 > !BF_HASH1
0 !BF_SIZE DO
1 + !BF_HASH2
0 UNTIL
1000 > !BF_HASH2
0 !BF_SIZE DO
1 + !BF_HASH3
0 UNTIL
1000 > !BF_HASH3
0 !BF_SIZE DO
1 + !BF_COUNT
0 UNTIL
1000 > !BF_COUNT
0 !BF_SIZE DO
1 + !BF_HASH1
1 + !BF_HASH2
1 + !BF_HASH3
0 UNTIL
100