Computes edit distance using dynamic programming in C#.

EditDistance.cs

public static int EditDistance(string str1, string 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 i = 0; i <= str2.Length; i++)
    {
        distance[0, i] = i;
    }
    for (int i = 1; i <= str1.Length; i++)
    {
        for (int j = 1; j <= str2.Length; j++)
        {
            distance[i, j] = Min(Min(distance[i-1, j], distance[i, j-1]), 
                                 distance[i-1, j-1] + (str1[i-1] == str2[j-1] ? 0 : 1));
        }
    }
    return distance[str1.Length, str2.Length];
}