AIMS_BD_IATI.WebAPI.Controllers.IATIImportController.getEditDistance C# (CSharp) Method

        protected int getEditDistance(string a, string b)
        {
            if (a.Length == 0) return b.Length;
            if (b.Length == 0) return a.Length;

            var matrix = new int[b.Length+1, a.Length+1];

            // increment along the first column of each row
            int i;
            for (i = 0; i <= b.Length; i++)
            {
                matrix[i, 0] = i;
            }

            // increment each column in the first row
            int j;
            for (j = 0; j <= a.Length; j++)
            {
                matrix[0, j] = j;
            }

            // Fill in the rest of the matrix
            for (i = 1; i <= b.Length; i++)
            {
                for (j = 1; j <= a.Length; j++)
                {
                    if (b[i - 1] == a[j - 1])
                    {
                        matrix[i, j] = matrix[i - 1, j - 1];
                    }
                    else
                    {
                        matrix[i, j] = Math.Min(matrix[i - 1, j - 1] + 1, // substitution
                            Math.Min(matrix[i, j - 1] + 1, // insertion
                                matrix[i - 1, j] + 1)); // deletion
                    }
                }
            }

            return matrix[b.Length, a.Length];
        }