What is Levenshtein distance and how to use this in golang

 The Levenshtein distance (also known as the edit distance) is a measure of the similarity between two strings. It is defined as the minimum number of single-character edits (insertions, deletions, or substitutions) required to change one string into the other. In other words, it is a way to calculate the difference between two words based on the number of operations needed to transform one word into the other.

The Levenshtein distance is often used in natural language processing, spell checking, and other applications where the similarity between two words needs to be calculated.

The algorithm for calculating the Levenshtein distance between two strings is relatively simple. It starts by creating a matrix of size (m+1) x (n+1), where m and n are the lengths of the two strings. Each cell in the matrix corresponds to a substring of one of the input strings. The algorithm then fills in the matrix by comparing the characters of the two strings one by one.

Here is an example of how the Levenshtein distance algorithm can be implemented in Go:

package main

import (
	"fmt"
)

func levenshteinDistance(s1, s2 string) int {
	m := len(s1)
	n := len(s2)
	d := make([][]int, m+1)
	for i := range d {
		d[i] = make([]int, n+1)
	}
	for i := 1; i <= m; i++ {
		d[i][0] = i
	}
	for j := 1; j <= n; j++ {
		d[0][j] = j
	}
	for j := 1; j <= n; j++ {
		for i := 1; i <= m; i++ {
			if s1[i-1] == s2[j-1] {
				d[i][j] = d[i-1][j-1]
			} else {
				d[i][j] = min(
					d[i-1][j]+1,
					d[i][j-1]+1,
					d[i-1][j-1]+1,
				)
			}
		}
	}
	return d[m][n]
}

func min(a, b, c int) int {
	if a < b && a < c {
		return a
	}
	if b < a && b < c {
		return b
	}
	return c
}

func main() {
	distance := levenshteinDistance("Pune", "pne")
	fmt.Println(distance)
}

        

In this example, the Levenshtein distance between the words "pune" and "pne" is 1, which corresponds to the single substitution of "u" for "n" that is needed to transform "pne" into "pune".