public static int distance(String s,
    String t) 
{
        int d[][]; // matrix
        int n; // length of s
        int m; // length of t
        int i; // iterates through s
        int j; // iterates through t
        char s_i; // ith character of s
        char t_j; // jth character of t
        int cost; // cost
        // Step 1
        n = s.length();
        m = t.length();
        if (n == 0)
            return m;
        if (m == 0)
            return n;
        d = new int[n+1][m+1];
        // Step 2
        for (i = 0; i < = n; i++)
            d[i][0] = i;
        for (j = 0; j < = m; j++)
            d[0][j] = j;
        // Step 3
        for (i = 1; i < = n; i++)
        {
            s_i = s.charAt (i - 1);
            // Step 4
            for (j = 1; j < = m; j++)
            {
                t_j = t.charAt(j - 1);
                // Step 5
                if (s_i == t_j)
                    cost = 0;
                else
                    cost = 1;
                // Step 6
                d[i][j] = minimum(d[i-1][j]+1, d[i][j-1]+1, d[i-1][j-1] + cost);
            }
        }
        // Step 7
        return d[n][m];
}