nodecounter

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

namespace mozesieuda
{
    public class Treenode
    {
        public int currentrow { get; set; }
        public int currentcolumn { get; set; }
        public IEnumerable<Treenode> Treenodes
        {
            get
            {

                if (FilesStream.map[currentrow - 1, currentcolumn - 1] == 'x' && currentrow - 1>=0 && currentcolumn - 1>=0)
                    yield return new Treenode { currentrow = currentrow - 1, currentcolumn = currentcolumn - 1 };
                if (FilesStream.map[currentrow - 1, currentcolumn] == 'x' && currentrow - 1>=0 && currentcolumn>=0)
                    yield return new Treenode { currentrow = currentrow - 1, currentcolumn = currentcolumn };
                if (FilesStream.map[currentrow - 1, currentcolumn + 1] == 'x' && currentrow - 1>=0 && currentcolumn <=FilesStream.columns-2)
                    yield return new Treenode { currentrow = currentrow - 1, currentcolumn = currentcolumn + 1 };
                if (FilesStream.map[currentrow, currentcolumn - 1] == 'x' && currentrow>=0 &&  currentcolumn - 1>=0)
                    yield return new Treenode { currentrow = currentrow, currentcolumn = currentcolumn - 1 };
                if (FilesStream.map[currentrow, currentcolumn + 1] == 'x' && currentrow>=0 && currentcolumn<=FilesStream.columns-2)
                    yield return new Treenode { currentrow = currentrow, currentcolumn = currentcolumn + 1 };
                if (FilesStream.map[currentrow + 1, currentcolumn - 1] == 'x' && currentrow<=FilesStream.rows-2 && currentcolumn - 1>=0)
                    yield return new Treenode { currentrow = currentrow + 1, currentcolumn = currentcolumn - 1 };
                if (FilesStream.map[currentrow + 1, currentcolumn] == 'x' && currentrow <=FilesStream.rows-2 && currentcolumn>=0)
                    yield return new Treenode { currentrow = currentrow + 1, currentcolumn = currentcolumn };
                if (FilesStream.map[currentrow + 1, currentcolumn + 1] == 'x' && currentrow <=FilesStream.rows-2 && currentcolumn <=FilesStream.columns-2)
                    yield return new Treenode { currentrow = currentrow + 1, currentcolumn = currentcolumn + 1 };
            }
        }
        public int? Counter()
        {
            int? counter = 1;
            FilesStream.counter++;
            if (currentrow == 0 || currentrow == FilesStream.rows - 1 || currentcolumn == 0 || currentcolumn == FilesStream.columns - 1)
            {
                return null;
            }
            foreach(var node in Treenodes)
            {
                FilesStream.map[node.currentrow, node.currentcolumn] = 'a';
                counter += node.Counter();
            }
            return counter;
        }

    }
}