JavaAlgorithms/Dynamic Programming/LevenshteinDistance.java
2019-04-20 21:58:35 +03:00

55 lines
1.6 KiB
Java

/**
* @author Kshitij VERMA (github.com/kv19971)
* LEVENSHTEIN DISTANCE dyamic programming implementation to show the difference between two strings (https://en.wikipedia.org/wiki/Levenshtein_distance)
*/
public class LevenshteinDistance {
private static int minimum(int a, int b, int c) {
if (a < b && a < c) {
return a;
} else if (b < a && b < c) {
return b;
} else {
return c;
}
}
private static int calculate_distance(String a, String b) {
int len_a = a.length() + 1;
int len_b = b.length() + 1;
int[][] distance_mat = new int[len_a][len_b];
for (int i = 0; i < len_a; i++) {
distance_mat[i][0] = i;
}
for (int j = 0; j < len_b; j++) {
distance_mat[0][j] = j;
}
for (int i = 0; i < len_a; i++) {
for (int j = 0; j < len_b; j++) {
int cost;
if (a.charAt(i) == b.charAt(j)) {
cost = 0;
} else {
cost = 1;
}
distance_mat[i][j] = minimum(distance_mat[i - 1][j], distance_mat[i - 1][j - 1], distance_mat[i][j - 1]) + cost;
}
}
return distance_mat[len_a - 1][len_b - 1];
}
public static void main(String[] args) {
String a = ""; // enter your string here
String b = ""; // enter your string here
System.out.print("Levenshtein distance between " + a + " and " + b + " is: ");
System.out.println(calculate_distance(a, b));
}
}