Part three of Levenshtein distance

lev_part_three.go

package main
import "fmt"

// PART THREE: if characters are not the same, we step through a comparison against each character to
////  determine DELETION, INSERTION, SUBSTITUTION and get the minimum of the three values.

func MinInt(a ...int) int {
  min := int(^uint(0) >> 1)
	for _, i := range a {
		if i < min {
			min = i
		}
	}
	return min
}

func LevenshteinThree(s1, s2 string) {
	m := len(s1)
	n := len(s2)
	width := n - 1
	fmt.Println("width =",width)
	vcell := make([]int, m * n)
	fmt.Println("making vcell",len(vcell), "elements long")

	// cells for i of m(s1)
	for i := 1; i < m; i++ {
		vcell[i * width + 0] = i
		fmt.Println("i=",i, "for len(str1)==",m, "at vector cell", vcell[i * width + 0]*width)
	}

	// cell for j of n(s2)
	for j := 1; j < n; j++ {
		vcell[0 * width + j] = j
		fmt.Println("j=",j, "for len(str2)==",n, "at vector cell", vcell[0 * width + j])
	}
	fmt.Println("Vector Cell:\n", vcell)
	fmt.Println("never compare 0-th index:", string(s1[0]),string(s2[0]))
	count := 0
	for j := 1; j < n; j++ {
		for i := 1; i < m; i++ {
			if s1[i] == s2[j] {
				fmt.Println("dropping into true for s1[i] == s2[j]",string(s1[i]),string(s2[j]))
				vcell[i * width + j] = vcell[(i - 1) * width + (j - 1)]
				count += 1
				fmt.Println(count)
			} else {
				fmt.Println(" &&&&& not true for s1[i] == s2[j]",string(s1[i]),string(s2[j]))
				deletion := vcell[(i - 1) * width + j] + 1
				fmt.Println(i,"- 1", "*",width,"+",j, "+ 1")
				fmt.Println("deletion:",deletion)
				insertion := vcell[(i * width + (j - 1))] + 1
				fmt.Println(i,"*",width,"+",j,"- 1 + 1")
				fmt.Println("insertion:",insertion)
				sub := vcell[((i - 1) * width + (j - 1))] + 1
				fmt.Println(i," - 1","*",width,"+",j,"- 1 + 1")
				fmt.Println("substitution:",sub)
				count += 1
				fmt.Println(count)
				fmt.Println("MinInt *************  :",MinInt(deletion,insertion,sub))
			}
		}
	}
	fmt.Println("operated on",count, "cells")
}

func main() {
	LevenshteinThree("str","str")
}

/*
*** OUTPUT
width = 2
making vcell 9 elements long
i= 1 for len(str1)== 3 at vector cell 2
i= 2 for len(str1)== 3 at vector cell 4
j= 1 for len(str2)== 3 at vector cell 1
j= 2 for len(str2)== 3 at vector cell 2
Vector Cell:
 [0 1 2 0 2 0 0 0 0]
never compare 0-th index: s s
dropping into true for s1[i] == s2[j] t t
1
 &&&&& not true for s1[i] == s2[j] r t
2 - 1 * 2 + 1 + 1
deletion: 1
2 * 2 + 1 - 1 + 1
insertion: 3
2  - 1 * 2 + 1 - 1 + 1
substitution: 3
2
MinInt *************  : 1
 &&&&& not true for s1[i] == s2[j] t r
1 - 1 * 2 + 2 + 1
deletion: 3
1 * 2 + 2 - 1 + 1
insertion: 1
1  - 1 * 2 + 2 - 1 + 1
substitution: 2
3
MinInt *************  : 1
dropping into true for s1[i] == s2[j] r r
4
operated on 4 cells
*/