Simple Implementation for calculating Distance.

The Distance is calculated with the help of the levensthein algorithm.
and the Results are stored in the pair form to make them easy to sort
This commit is contained in:
aditya-K2 2021-11-14 22:07:39 +05:30
parent 228f69ef75
commit 5aed3d0604

90
search/searchUtils.go Normal file
View File

@ -0,0 +1,90 @@
package search
import (
"fmt"
"math"
"math/bits"
"strings"
)
type Pair struct {
Key string
Value int
}
type PairList []Pair
func (p PairList) Len() int { return len(p) }
func (p PairList) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p PairList) Less(i, j int) bool { return p[i].Value < p[j].Value }
func ConvertToBitMap(b string) uint64 {
b = strings.ToLower(b)
var a uint64 = 0
for _, i := range b {
asc := (int(i) - 97)
if asc >= 97 && asc <= 122 {
a |= 1 << asc
}
}
return a
}
func CalculateUpperBound(a, b string) float64 {
aB := ConvertToBitMap(a)
bB := ConvertToBitMap(b)
lengthAf64 := float64(len(a))
lengthBf64 := float64(len(b))
m := math.Min(lengthAf64, lengthBf64) - float64(bits.OnesCount64(aB&(^bB)))
return (1.0 / 3.0) * ((float64(m) / float64(len(a))) + (float64(m) / float64(len(b))) + 1)
}
func min(a, b, c int) int {
if a > b && b < c {
return b
} else if b > a && a < c {
return a
} else {
return c
}
}
func cost(i, j rune) int {
if i != j {
return 1
} else {
return 0
}
}
func GetLevenshteinDistance(a, b string) int {
c := []rune(a)
e := []rune(b)
m, n := len(c), len(e)
d := make([][]int, m+1)
for i := range d {
d[i] = make([]int, n+1)
}
for i := range d {
for j := range d[i] {
if j == 0 {
d[i][j] = i
} else if i == 0 {
d[i][j] = j
} else {
d[i][j] = 0
}
}
}
for j := 1; j < n+1; j++ {
for i := 1; i < m+1; i++ {
d[i][j] = min(d[i-1][j-1]+cost(c[i-1], e[j-1]),
d[i][j-1]+1,
d[i-1][j]+1)
}
}
return d[m][n]
}
func main() {
fmt.Println(GetLevenshteinDistance("cat", "wildcat"))
}