https://github.com/emeraldacoustics/knuth-morris-pratt

An easy-to-use class that implements Knuth-Morris-Pratt algorithm.
https://github.com/emeraldacoustics/knuth-morris-pratt

Last synced: 9 days ago
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An easy-to-use class that implements Knuth-Morris-Pratt algorithm.

• Host: GitHub
• URL: https://github.com/emeraldacoustics/knuth-morris-pratt
• Owner: emeraldacoustics
• License: mit
• Created: 2024-04-24T22:23:38.000Z (7 months ago)
• Default Branch: main
• Last Pushed: 2024-04-25T01:44:19.000Z (7 months ago)
• Last Synced: 2024-07-25T02:16:53.728Z (4 months ago)
• Language: C++
• Size: 8.79 KB
• Stars: 7
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# knuth-morris-pratt

An easy-to-use class that implements Knuth-Morris-Pratt algorithm.

This class can handle any data types.

For example, `KnuthMorrisPratt KMP;` or `KnuthMorrisPratt KMP;`.

`build()` method calculates suffix links for the give array passed as a parameter.

You can easily access suffix link values via the index operator.

Suffix link values are stored in `f`.

If `f[x]` equals `y`, `p[:x]` both begins with and ends with `p[:y]`.

Refer example.cpp to see how it works.

```cpp

#include 

#include "knuth-morris-pratt-dynamic.hpp"

using namespace std;

int main()

{

	ios::sync_with_stdio(false);

	string txt, pat;

	cin >> txt >> pat;

	/*

	 * Prepare a vector to be processed by the build method

	 * This could be a bit annoying for manipulating strings,

	 * but will prove useful for handling other data types.

	 */

	vector patv(pat.length(), 0);

	for (int i = 0; i < pat.length(); i++)

		patv[i] = pat[i];

	

	KnuthMorrisPratt KMP;

	KMP.build(patv);

	vector res;

	for (int i = 0, k = 0; i < txt[i]; i++)

	{

		for (; k > 0 && (k == pat.length() || txt[i] != pat[k]); k = KMP[k]);

		if (txt[i] == pat[k])

			k++;

		

		// Found a pattern

		if (k == pat.length())

			res.push_back(i - pat.length() + 1);

	}

	for (const auto & x : res)

		cout << x << endl;

	return 0;

}

```