IsAlmostPalindrome.cs

public static bool IsAlmostPalindrome(string word)
        {
            char[] normal = word.ToCharArray();
            char[] reverse = word.ToCharArray();
            Array.Reverse(reverse);
            
            // Manualmente
            //for (int i = normal.Length - 1, j = 0; i >= 0 ; i--, j++)
            //{
            //    reverse[i] = normal[j];
            //}

            int erroCount = 0;
            for (int i = 0; i < normal.Length; i++)
            {
                if (reverse[i] != normal[i])
                    erroCount += 1;                
            }

            if(erroCount > 2)            
                return false;
            
            return true;
        }

Checks whether a given string is palindrome. Also return true whether it is almost palindrome whith error rate at most one char.