Levenshtein DFA in .NET

Question

Good afternoon,

Does anyone know of an \"out-of-the-box\" implementation of Levenshtein DFA (deterministic finite automata) in .NET (or easily translatable to i

Answer 1

Here you go.

/// 

/// Levenshtein Distance Calculator
/// 
public static int DistanceFrom(this string s, string t)
{
    int n = s.Length;
    int m = t.Length;
    int[,] d = new int[n + 1, m + 1];

    // Step 1
    if (n == 0)
        return m;

    if (m == 0)
        return n;

    // Step 2
    for(int i = 0; i <= n; d[i, 0] = i++) ;
    for(int j = 0; j <= m; d[0, j] = j++) ;

    // Step 3
    for (int i = 1; i <= n; i++)
    {
        //Step 4
        for (int j = 1; j <= m; j++)
        {
            // Step 5
            int cost = (t[j - 1] == s[i - 1]) ? 0 : 1;

            // Step 6
            d[i, j] = Math.Min(
                Math.Min(d[i - 1, j] + 1, d[i, j - 1] + 1),
                d[i - 1, j - 1] + cost);
        }
    }
    // Step 7
    return d[n, m];
}