Levenshtein CLR

///<summary>
///This will be the code file to hold any CLR funcitons that the apex team uses.
///</summmary>

/******Compiler Flags:******
/fullpaths
/platform:x64
/nologo
/target:library
****************************/

using System;
using System.Data.SqlTypes;

public partial class UserDefinedFunctions
{
[Microsoft.SqlServer.Server.SqlFunction(IsDeterministic = true, IsPrecise = false)]
    public static SqlInt32 Levenshtein(SqlString S1, SqlString S2)
    {
        if (S1.IsNull || S2.IsNull)
            throw (new ArgumentNullException());

        int n = S1.Value.Length;
        int m = S2.Value.Length;

        int[,] d = new int[n + 1, m + 1];
        int cost = 0;

        if (n == 0)
            return m;
        if (m == 0)
            return n;

        for (int i = 0; i <= n; i++)
            d[i, 0] = i;

        for (int j = 0; j <= m; j++)
            d[0, j] = j;

        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; j <= m; j++)
            {
                if (S1.Value[i-1] == S2.Value[j-1])
                    cost = 0;
                else
                    cost = 1;

                d[i, j] = System.Math.Min(System.Math.Min(d[i - 1, j] + 1, d[i, j - 1] + 1), d[i - 1, j - 1] + cost);
            }
        }

        return d[n, m];
    }
}