44 lines
1.0 KiB
Go
44 lines
1.0 KiB
Go
package fuzzy
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// LevenshteinDistance measures the difference between two strings.
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// The Levenshtein distance between two words is the minimum number of
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// single-character edits (i.e. insertions, deletions or substitutions)
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// required to change one word into the other.
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//
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// This implemention is optimized to use O(min(m,n)) space and is based on the
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// optimized C version found here:
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// http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Levenshtein_distance#C
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func LevenshteinDistance(s, t string) int {
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r1, r2 := []rune(s), []rune(t)
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column := make([]int, len(r1)+1)
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for y := 1; y <= len(r1); y++ {
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column[y] = y
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}
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for x := 1; x <= len(r2); x++ {
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column[0] = x
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for y, lastDiag := 1, x-1; y <= len(r1); y++ {
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oldDiag := column[y]
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cost := 0
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if r1[y-1] != r2[x-1] {
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cost = 1
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}
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column[y] = min(column[y]+1, column[y-1]+1, lastDiag+cost)
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lastDiag = oldDiag
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}
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}
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return column[len(r1)]
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}
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func min(a, b, c int) int {
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if a < b && a < c {
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return a
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} else if b < c {
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return b
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}
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return c
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}
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