JavaAlgorithms/Dynamic Programming/LevenshteinDistance.java

56 lines
1.3 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; i < 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));
}
}