散列正克用循环多项式 - java实现 [英] Hashing n-grams by cyclic polynomials - java implementation

问题描述

我解决了一些问题，涉及拉宾，卡普字符串搜索算法。该算法需要滚动哈希要快那么天真的搜索。 这篇文章介绍如何实现滚动哈希值。我实现了拉宾，卡普滚动哈希没有问题，发现几个实现实施，而且文中还提到了计算的复杂性和散列正克用循环多项式为prefered。它链接到<一个href="https://www.se.auckland.ac.nz/courses/SOFTENG250/archive/2006/assignments/Hashing/BuzHash.java"相对=nofollow> BuzHash 实现这样的技术，但我不知道如何可以用来构建正克散在它的上面。我想有一些像这个或

I'm solving some problem that involves Rabin–Karp string search algorithm. This algorithm requires rolling hash to be faster then naive search. This article describes how to implement rolling hash. I implemented "Rabin-Karp rolling hash" without problems and found few implementations implementations, but article also mentions computational complexity and that hashing n-grams by cyclic polynomials is prefered. It links to BuzHash implementation of such technique but I wonder how it can be used to build n-gram hash on top of it. I want to have something like this or

CPHash cp = new CPHash("efghijk");
cp.shiftRight('l') // now we got hash of "fghijki"
cp.shiftLeft('d') // "defghi"

有关Java的。

有关的人谁都会遇到字符串搜索（像我）有一些文章，我发现有用的相关的问题：的 1 ， 2 ， 3

For people who will encounter problems related with string search (like me) there are some articles that I found usefull: 1, 2, 3

推荐答案

我最近发表的一个Apache许可的，它实现几个滚动散列功能，包括循环和拉宾，卡普Java库：

I recently published an Apache licensed Java library which implements several rolling hash functions including Cyclic and Rabin-Karp:

HTTP：//$c$c.google.com/p/rollinghashjava/

https://github.com/lemire/rollinghashjava

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