public static int Find(string FWord, string SWord, bool Damerau = false)
{
var n = FWord.Length + 1;
var m = SWord.Length + 1;
var matrix = new int[n, m];
const int deletionCost = 1;
const int insertionCost = 1;
for (int i = 0; i < n; i++)
{
matrix[i, 0] = i;
}
for (int j = 0; j < m; j++)
{
matrix[0, j] = j;
}
for (int i = 1; i < n; i++)
{
for (int j = 1; j < m; j++)
{
var substrCost = FWord[i - 1] == SWord[j - 1] ? 0 : 1;
matrix[i, j] = Minimum.Find(
matrix[i - 1, j] + deletionCost,
matrix[i, j - 1] + insertionCost,
matrix[i - 1, j - 1] + substrCost);
if (Damerau == true)
{
if (i > 1 && j > 1 &&
FWord[i - 1] == SWord[j - 2] &&
FWord[i - 2] == SWord[j - 1])
{
matrix[i, j] = Minimum.Find(matrix[i, j],
matrix[i - 2, j - 2] + substrCost);
}
}
}
}
return(matrix[n - 1, m - 1]);
}
