An improvement on capturing similarity between strings

/*
Matching two strings
Author: Thanh Ngoc Dao - Thanh.dao@gmx.net
Copyright (c) 2005 by Thanh Ngoc Dao.
*/
using System;

namespace WordsMatching
{
	/// <summary>
	/// Summary description for Leven.
	/// </summary>
	internal class Leven: ISimilarity
	{
		private int Min3(int a, int b, int c)
		{
			return System.Math.Min(System.Math.Min(a, b), c);			
		}

		private int ComputeDistance (string s, string t) 
		{
			int n=s.Length;
			int m=t.Length;
			int[,] distance=new int[n + 1, m + 1]; // matrix
			int cost=0; 

			if(n == 0) return m;
			if(m == 0) return n;			
			//init1
			for(int i=0; i <= n; distance[i, 0]=i++);			
			for(int j=0; j <= m; distance[0, j]=j++);

			//find min distance
			for(int i=1; i <= n; i++) 
			{
				for(int j=1; j <= m;j++) 
				{
					cost=(t.Substring(j - 1, 1) == s.Substring(i - 1, 1) ? 0 : 1);					
					distance[i,j]=Min3(distance[i - 1, j] + 1, 
						distance[i, j - 1] + 1, 
						distance[i - 1, j - 1] + cost);
				}
			}

			return distance[n, m];
		}

		public float GetSimilarity(System.String string1, System.String string2)
		{
			
			float dis=ComputeDistance(string1, string2);
			float maxLen=string1.Length;
			if (maxLen < (float) string2.Length)
				maxLen = string2.Length;

			float minLen=string1.Length;
			if (minLen > (float) string2.Length)
				minLen = string2.Length;

			
			if (maxLen == 0.0F)
				return 1.0F;
			else
			{
				return maxLen - dis;
				//return 1.0F - dis/maxLen ;
				//return (float) Math.Round(1.0F - dis/maxLen, 1) * 10 ;
			}
		}

		public Leven()
		{
			//
			// TODO: Add constructor logic here
			//
		}
	}
}