Knight Path

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace KnightPath
{
    class KnightPath
    {
        static void Main()
        {
            int n = 1;
            int[] arr = new int[8];
            arr[0] = 1;
            int pos = 0;
            int row = 0;
            for (int i = 0; i < 25; i++)
            {
                string command = Console.ReadLine();
                if (command == "stop")
                {
                    break;
                }

                if (command == "left down")
                {
                    pos += 2;
                    row += 1;
                    if (CheckValidPosition(row,pos))
                    {
                        n <<= 2;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos -= 2;
                        row -= 1;
                    }
                }
                if (command == "left up")
                {
                    pos += 2;
                    row -= 1;
                    if (CheckValidPosition(row, pos))
                    {

                        n <<= 2;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos -= 2;
                        row += 1;
                    }
                }
                if (command == "right up")
                {
                    pos -= 2;
                    row -= 1;
                    if (CheckValidPosition(row, pos))
                    {

                        n >>= 2;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos += 2;
                        row += 1;
                    }
                }
                if (command == "right down")
                {
                    pos -= 2;
                    row += 1;
                    if (CheckValidPosition(row, pos))
                    {

                        n >>= 2;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos += 2;
                        row -= 1;
                    }
                }
                if (command == "up left")
                {
                    pos += 1;
                    row -= 2;
                    if (CheckValidPosition(row, pos))
                    {

                        n <<= 1;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos -= 1;
                        row += 2;
                    }
                }
                if (command == "down left")
                {
                    pos += 1;
                    row += 2;
                    if (CheckValidPosition(row, pos))
                    {

                        n <<= 1;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos -= 1;
                        row -= 2;
                    }
                }
                if (command == "up right")
                {
                    pos -= 1;
                    row -= 2;
                    if (CheckValidPosition(row, pos))
                    {

                        n >>= 1;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos += 1;
                        row += 2;
                    }
                }
                if (command == "down right")
                {
                    pos -= 1;
                    row += 2;
                    if (CheckValidPosition(row, pos))
                    {

                        n >>= 1;
                        arr[row] = arr[row] ^ n;
                    }
                    else
                    {
                        pos += 1;
                        row -= 2;
                    }
                }
            }
            if (Array.TrueForAll(arr, y => y == 0))
            {
                Console.WriteLine("[Board is empty]");
            }
            else
            {
                for (int i = 0; i < 8; i++)
                {
                    if (arr[i] != 0)
                    {
                        Console.WriteLine(arr[i]);
                    }
                }
            }
        }

        private static bool CheckValidPosition(int row, int pos)
        {
            if (pos >= 0 && pos < 8 && row >= 0 && row < 8)
            {

                return true;
            }
            return false;

        }
    }
}