Programming Basics Exam 26 April 2015 Evening,ProbGameOFLife

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


class Program
{
    static void Main()
    {
        int pairs = int.Parse(Console.ReadLine());
        int[] oldboard = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
        int x; int y;
        List<int> newboard = new List<int>{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
       // List<int> coordinates = new List<int>();
        for (int i = 0; i < pairs; i++)
        {
            x = int.Parse(Console.ReadLine());
            y = int.Parse(Console.ReadLine());
            oldboard[x] |= (1 << y);
            //coordinates.Add(x);
            //coordinates.Add(y);
        }
        //foreach (var s in oldboard)
        //{
        //    Console.WriteLine(Convert.ToString(s, 2).PadLeft(10, '0'));
        //}

        for (int red =0; red < 10; red++)// minavam prez vcseki edin bit
        {
            //foreach (var row in newboard)
            //{
            //    Console.WriteLine(Convert.ToString(row, 2).PadLeft(10, '0'));
            //}
            Console.WriteLine();
            for (int kol = 9; kol >=0; kol--)
            {

                int currentbit = (oldboard[red] & (1 << kol)) == 0 ? 0 : 1;
                int checkedbit;
                int countones = 0;
                int startred = Math.Max(red - 1, 0);// opredelqv koi susedni bitove da proverqvam
                int endred = Math.Min(red + 1, 9);
                int startkol = Math.Min(kol + 1, 9);
                int endkol = Math.Max(kol - 1, 0);
                for (int k = startred; k <= endred; k++)
                {
                    for (int l = startkol; l >= endkol; l--)
                    {
                        if (k==red&&l==kol)
                        {
                            continue;
                        }
                        checkedbit = (oldboard[k]&(1<<l)) != 0 ? 1 : 0;
                        if (checkedbit==1)
                        {
                            countones++;
                        }
                    }
                }

                if (currentbit == 1)
                {
                    if (countones < 2 || 3 < countones)
                    {
                        newboard[red] &= ~(1 << kol);
                    }
                    else
                    {
                        newboard[red] |= (1 << kol);
                    }
                }
                else
                {
                    if (countones == 3)
                    {
                        newboard[red] |= (1 << kol);
                    }
                }
            }
        }

        //Console.WriteLine(Convert.ToString(newboard[2],2));//pravq proverka kolko tretoto 4islo -zero testa dava razlika samo v nego
        foreach (var row in newboard)
        {
            Console.WriteLine(Convert.ToString(row, 2).PadLeft(10, '0'));
        }
    }
}