using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        int[] arr = {1,2,1,1,2,2,2,2,0,0,0,0,0};

        var item = SortArray(arr);

        foreach(int i in item)

        {

            Console.Write(i);

        }

    }

    private static int[] SortArray(int[] arr)

    {

        int hi=arr.Length-1;

        int lo = 0;

        int mid =0;

        while ( mid<=hi )

        {

            if ( arr[mid] == 0 )

            {

                int temp = arr[lo];

                arr[lo] = arr[mid];

                arr[mid] = temp;

                mid++;

                lo++;

            }

            else if ( arr[mid] == 2 )

            {

                int temp = arr[hi];

                arr[hi] = arr[mid];

                arr[mid] = temp;

​

                hi--;

            }

            else

            {

                mid++;

            }

        }

        return arr;

    }

}