https://github.com/leonardpepa/string-matching-go

String matching algorithms written in go
https://github.com/leonardpepa/string-matching-go

algorithms brute-force dfa go golang introduction-to-algorithms knuth-morris-pratt rabin-karp-algorithm string-matching

Last synced: 27 days ago
JSON representation

String matching algorithms written in go

• Host: GitHub
• URL: https://github.com/leonardpepa/string-matching-go
• Owner: Leonardpepa
• Created: 2024-01-03T03:32:17.000Z (10 months ago)
• Default Branch: master
• Last Pushed: 2024-01-07T21:32:11.000Z (10 months ago)
• Last Synced: 2024-01-24T12:07:02.940Z (10 months ago)
• Topics: algorithms, brute-force, dfa, go, golang, introduction-to-algorithms, knuth-morris-pratt, rabin-karp-algorithm, string-matching
• Language: Go
• Homepage: https://github.com/Leonardpepa/string-matching-go?tab=readme-ov-file
• Size: 1.68 MB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# String matching algorithms written in go

## Purpose

* Educational

## Description

This project is an implementation of various string matching algorithms described

in [Introduction to algorithms](https://dl.ebooksworld.ir/books/Introduction.to.Algorithms.4th.Leiserson.Stein.Rivest.Cormen.MIT.Press.9780262046305.EBooksWorld.ir.pdf)


## Algorithms Implemented

* Brute force

* Rabin Karp

* DFA (Deterministic finite automaton)

* Knuth Morris Pratt

## Time Complexity

 * n = length of the input text

 * m = length of the pattern

 * This table shows the worst case time

  

    Algorithms

    Preprocessing time

    Matching time

  

  

    Brute Force

    0

    Ο((n - m + 1)m)

  

    Rabin Karp

    Θ(m)

    Ο((n - m + 1)m)

  

    DFA

    Ο(m |Σ|)

    Θ(n)

  

    Knuth Morris Pratt

    Θ(m)

    Θ(n)

  

### String Matching Definition

The problem of finding occurrence(s) of a pattern string within another string or body of text.

The algorithm returns an array of the first index for every occurrence in the text

## Example

```go

package main

import (

	"fmt"

	"log"

	"string-matching/internal/KMP"

)

func main() {

	input := `Project Gutenberg's International Short Stories: French, by Various

This eBook is for the use of anyone anywhere at no cost and with

almost no restrictions whatsoever.  You may copy it, give it away or

re-use it under the terms of the Project Gutenberg License included

with this eBook or online at www.gutenberg.net

`

	pattern := "Gutenberg"

	indexes, err := KMP.MatchString(input, pattern)

	if err != nil {

		log.Fatal(err)

	}

	printMatches(indexes, input, len(pattern))

}

func printMatches(indexes []int, input string, patternLen int) {

	for _, index := range indexes {

		fmt.Printf("found at %d, %s\n", index, input[index:index+patternLen])

	}

}

```

### output

```terminal

found at 8, Gutenberg

found at 244, Gutenberg

```

# How to run

1. Clone the repo ```git clone https://github.com/Leonardpepa/string-matching-go.git```

2. Build ```go build```

3. run on windows```string-matching.exe```

4. run on linux ```./string-matching```

5. run tests ```go test```