/*
* Copyright 2008-2011 Grant Ingersoll, Thomas Morton and Drew Farris
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* -------------------
* To purchase or learn more about Taming Text, by Grant Ingersoll, Thomas Morton and Drew Farris, visit
* http://www.manning.com/ingersoll
*/
package com.tamingtext.fuzzy;
public class LevenshteinDistance {
//<start id="ed-levenshtein"/>
public int levenshteinDistance(char s[], char t[]) {
int m = s.length;
int n = t.length;
int d[][] = new int[m+1][n+1]; //<co id="co.fuzzy.levenshtein.distance"/>
for (int i=0;i<=m;i++) //<co id="co.fuzzy.levenshtein.init1"/>
d[i][0] = i;
for (int j=0;j<=n;j++)
d[0][j] = j;
for (int j=1;j<=n;j++) {
for (int i=1;i<=m;i++) {
if (s[i-1] == t[j-1]) {
d[i][j] = d[i-1][j-1];//<co id="co.fuzzy.levenshtein.match"/>
} else {
d[i][j] = Math.min(Math.min(
d[i-1][j] + 1, //<co id="co.fuzzy.levenshtein.insertion"/>
d[i][j-1] + 1),
d[i-1][j-1] + 1);
}
}
}
return d[m][n];
}
/*
<calloutlist>
<callout arearefs="co.fuzzy.levenshtein.distance"><para>Allocate the distance matrix.</para></callout>
<callout arearefs="co.fuzzy.levenshtein.init1"><para>Initialize an upper bound on distance.</para></callout>
<callout arearefs="co.fuzzy.levenshtein.match"><para>Cost is the same as the previous match.</para></callout>
<callout arearefs="co.fuzzy.levenshtein.insertion"><para>Cost is one for an insertion, deletion, or substitution.</para></callout>
</calloutlist>
*/
//<end id="ed-levenshtein"/>
}