mirror of https://github.com/sbt/sbt.git
37 lines
1.0 KiB
Scala
37 lines
1.0 KiB
Scala
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package sbt.complete
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/** @author Paul Phillips*/
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object EditDistance {
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/** Translated from the java version at
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* http://www.merriampark.com/ld.htm
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* which is declared to be public domain.
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*/
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def levenshtein(s: String, t: String, insertCost: Int, deleteCost: Int, subCost: Int, transposeCost: Int, transpositions: Boolean = false): Int = {
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val n = s.length
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val m = t.length
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if (n == 0) return m
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if (m == 0) return n
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val d = Array.ofDim[Int](n + 1, m + 1)
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0 to n foreach (x => d(x)(0) = x)
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0 to m foreach (x => d(0)(x) = x)
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for (i <- 1 to n ; val s_i = s(i - 1) ; j <- 1 to m) {
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val t_j = t(j - 1)
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val cost = if (s_i == t_j) 0 else 1
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val c1 = d(i - 1)(j) + deleteCost
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val c2 = d(i)(j - 1) + insertCost
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val c3 = d(i - 1)(j - 1) + cost*subCost
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d(i)(j) = c1 min c2 min c3
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if (transpositions) {
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if (i > 1 && j > 1 && s(i - 1) == t(j - 2) && s(i - 2) == t(j - 1))
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d(i)(j) = d(i)(j) min (d(i - 2)(j - 2) + cost*transposeCost)
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}
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}
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d(n)(m)
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}
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}
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