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