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mirror of https://github.com/miguelmota/cointop synced 2024-11-14 18:12:57 +00:00
cointop/pkg/levenshtein/levenshtein.go
Simon Roberts e1aded93e8
More minor cleanups (no functional change) (#198)
* Redundant type conversions

* Remove redudant type declarations. Inline one-line constructors. Remove unnecessary brackets.

* Simplify name - it's used via package name anyway

* Simplify variable initializations

* Change `var x uint = Y` to `x := uint(Y)`

* More shorthand initialization
2021-10-05 08:01:42 +11:00

56 lines
1.3 KiB
Go

package levenshtein
import (
"math"
"strings"
)
// DamerauLevenshteinDistance calculates the damerau-levenshtein distance between s1 and s2.
// Reference: [Damerau-Levenshtein Distance](http://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance)
// Note that this calculation's result isn't normalized. (not between 0 and 1.)
// and if s1 and s2 are exactly the same, the result is 0.
func DamerauLevenshteinDistance(s1, s2 string) int {
if s1 == s2 {
return 0
}
s1Array := strings.Split(s1, "")
s2Array := strings.Split(s2, "")
lenS1Array := len(s1Array)
lenS2Array := len(s2Array)
m := make([][]int, lenS1Array+1)
var cost int
for i := range m {
m[i] = make([]int, lenS2Array+1)
}
for i := 0; i < lenS1Array+1; i++ {
for j := 0; j < lenS2Array+1; j++ {
if i == 0 {
m[i][j] = j
} else if j == 0 {
m[i][j] = i
} else {
cost = 0
if s1Array[i-1] != s2Array[j-1] {
cost = 1
}
m[i][j] = min(m[i-1][j]+1, m[i][j-1]+1, m[i-1][j-1]+cost)
if i > 1 && j > 1 && s1Array[i-1] == s2Array[j-2] && s1Array[i-2] == s2Array[j-1] {
m[i][j] = min(m[i][j], m[i-2][j-2]+cost)
}
}
}
}
return m[lenS1Array][lenS2Array]
}
// min returns the minimum number of passed int slices.
func min(is ...int) int {
min := math.MaxInt32
for _, v := range is {
if min > v {
min = v
}
}
return min
}