-
Notifications
You must be signed in to change notification settings - Fork 5
/
Levenshtein.java
39 lines (36 loc) · 1.21 KB
/
Levenshtein.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
package org.genericsystem.cv;
public class Levenshtein {
/**
* Computes the Levenshtein distance between two strings.
*
* @param a - the first string
* @param b - the second string
* @return an {@code int} representing the cost
*/
public static int distance(String a, String b) {
a = a.toLowerCase();
b = b.toLowerCase();
// i == 0
int[] costs = new int[b.length() + 1];
for (int j = 0; j < costs.length; j++)
costs[j] = j;
for (int i = 1; i <= a.length(); i++) {
// j == 0; nw = lev(i - 1, j)
costs[0] = i;
int nw = i - 1;
for (int j = 1; j <= b.length(); j++) {
int cj = Math.min(1 + Math.min(costs[j], costs[j - 1]), a.charAt(i - 1) == b.charAt(j - 1) ? nw : nw + 1);
nw = costs[j];
costs[j] = cj;
}
}
// System.out.print(">>> Levenshtein a : \"" + a + "\"" + " | b : \"" + b + "\"");
// System.out.println(" | cost : " + costs[b.length()]);
return costs[b.length()];
}
public static void main(String[] args) {
String[] data = { "kitten", "sitting", "saturday", "sunday", "rosettacode", "raisethysword" };
for (int i = 0; i < data.length; i += 2)
System.out.println("distance(" + data[i] + ", " + data[i + 1] + ") = " + distance(data[i], data[i + 1]));
}
}