code: package gr.uom.java.ast.util.math;
  
  public class LevenshteinDistance {
  	private static int minimum(int a, int b, int c) {
  		return Math.min(Math.min(a, b), c);
  	}
  
  	public static int computeLevenshteinDistance(CharSequence str1,
  			CharSequence str2) {
  		int[][] distance = new int[str1.length() + 1][str2.length() + 1];
  
  		for (int i = 0; i <= str1.length(); i++)
  			distance[i][0] = i;
  		for (int j = 1; j <= str2.length(); j++)
  			distance[0][j] = j;
  
  		for (int i = 1; i <= str1.length(); i++)
  			for (int j = 1; j <= str2.length(); j++)
  				distance[i][j] = minimum(
  						distance[i - 1][j] + 1,
  						distance[i][j - 1] + 1,
  						distance[i - 1][j - 1]
  								+ ((str1.charAt(i - 1) == str2.charAt(j - 1)) ? 0
  										: 1));
  		return distance[str1.length()][str2.length()];
  	}
  }
  