2024day17singleDigits

public static class Day17
{
    public static string Solve1(string input) => string.Join(',', Solve(SplitNumbers(input).First));

    public static long Solve2(string input)
    {
        long[] expect = input.Split(Environment.Newline + Environment.Newline)[1].Replace("Program: ", string.Empty).Split(",").Select(long.Parse).ToArray();
        long A = 0L;
        int j = 15;
        bool ok = true;
        while (j >= 0)
        {
            int i = 0;
            int t = ok || A % 8L > 0L ? (int)(A % 8L) : 8;
            for (i = t; i < 8; i++)
            {
                if (Crunch(A) == expect[j])
                    break;
                A += 1L;
            }
            if (i == 8)
            {
                A = A / 8L;
                ok = false;
                j += 1;
            }
            else
            {
                A = A * 8L;
                ok = true;
                j -= 1;
            }
        }
        return A / 8L;
    }

    // Interpreted Crunch,0,3,3,0
    private static IEnumerable<long> Solve(long @init)
    {
        while (@init > 0L)
        {
            yield return Crunch(@init);
            @init = @init >> 3;
        }
    }

    // Interpreted 2,4,1,5,7,5,1,6,4,2,5,5
    private static long Crunch(long A)
    {
        int R = (int)(A % 8L);
        int R101 = R ^ 5;
        return (R101 ^ 6 ^ A >> R101) % 8L;
    }
}