所有匹配的 Boyer

本文介绍了所有匹配的 Boyer-Moore-Horspool 算法(在 Byte 数组中查找 Byte 数组)的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

这是我对 BMH 算法的实现(它就像一个魅力):

Here is my implementation of BMH algorithm (it works like a charm):

public static Int64 IndexOf(this Byte[] value, Byte[] pattern) { if (value == null) throw new ArgumentNullException("value"); if (pattern == null) throw new ArgumentNullException("pattern"); Int64 valueLength = value.LongLength; Int64 patternLength = pattern.LongLength; if ((valueLength == 0) || (patternLength == 0) || (patternLength > valueLength)) return -1; Int64[] badCharacters = new Int64[256]; for (Int64 i = 0; i < 256; ++i) badCharacters[i] = patternLength; Int64 lastPatternByte = patternLength - 1; for (Int64 i = 0; i < lastPatternByte; ++i) badCharacters[pattern[i]] = lastPatternByte - i; // Beginning Int64 index = 0; while (index <= (valueLength - patternLength)) { for (Int64 i = lastPatternByte; value[(index + i)] == pattern[i]; --i) { if (i == 0) return index; } index += badCharacters[value[(index + lastPatternByte)]]; } return -1; }

我试图修改它以返回所有匹配项而不是仅返回第一个索引，但我在任何地方都收到 IndexOutOfRangeException D:

I tried to modify it in order to return all the matches instead of only the first index, but I'm getting IndexOutOfRangeException everywhere D:

显然我遗漏了一些重要的东西，或者我没有正确理解它是如何工作的.我做错了什么?

Obviously I'm missing something important or I didn't properly understood how it works. What am I doing wrong?

public static List<Int64> IndexesOf(this Byte[] value, Byte[] pattern) { if (value == null) throw new ArgumentNullException("value"); if (pattern == null) throw new ArgumentNullException("pattern"); Int64 valueLength = value.LongLength; Int64 patternLength = pattern.LongLength; if ((valueLength == 0) || (patternLength == 0) || (patternLength > valueLength)) return (new List<Int64>()); Int64[] badCharacters = new Int64[256]; for (Int64 i = 0; i < 256; ++i) badCharacters[i] = patternLength; Int64 lastPatternByte = patternLength - 1; for (Int64 i = 0; i < lastPatternByte; ++i) badCharacters[pattern[i]] = lastPatternByte - i; // Beginning Int64 index = 0; List<Int64> indexes = new List<Int64>(); while (index <= (valueLength - patternLength)) { for (Int64 i = lastPatternByte; value[(index + i)] == pattern[i]; --i) { if (i == 0) indexes.Add(index); } index += badCharacters[value[(index + lastPatternByte)]]; } return indexes; }

推荐答案

更改

if (i == 0) indexes.Add(index);

到

if (i == 0) { indexes.Add(index); break; }