Редици.01.01.Най-дългата еднаква поредица в string

using System;
class LongestEqualSubsequence
{
    static void Main()
    {
        string str = "JJsaaadd";
        FindLongestEqualSubs(str);
    }

    static void FindLongestEqualSubs(string str)
    {
        int len = 1, bestLen = 0, endIndex = 0;

        for (int i = 0; i < str.Length - 1; i++)
        {
            if(str[i] == str[i + 1])
            {
                len++;

            }
            else if (bestLen < len)
            {
                bestLen = len;
                endIndex = i;
                len = 1;
            }
            else
            {
                len = 1;
            }
        }
        if(len > bestLen)
        {
            bestLen = len;
            endIndex = str.Length - 1;
        }
        Console.WriteLine("Appearing: " + bestLen);
        Console.Write("Subsequence : ");
        for (int i = endIndex - bestLen + 1; i <= endIndex; i++)
        {
            Console.Write(str[i]);
        }
        Console.WriteLine();
    }
}