GrayCode-Recursion

using System;
using System.Collections.Generic;

public class Program
{
    /*
    public static int[] GrayCode(int k)
    {
        int[] result = {1};
        for(int n = 1; n < k; n++)
        {
            int[] newres = new int[2*result.Length + 1];
            int i = 0;
            for(i = 0; i < result.Length; i++)
                newres[i] = result[i];
            newres[i] = n+1; i++;
            for(int j = i; j <= 2*result.Length; j++)
                newres[j] = result[j-i];
            result = newres;
        }
        return result;
    }
    */

    public static int[] GrayCode(int k){
        List<int> list = new List<int>();
        GrayCode(0, k, list);
        return list.ToArray();
    }


    public static void GrayCode(int n, int k, List<int> list){
        if (k == n){
            return;
        }
        GrayCode(n, k - 1, list);
        list.Add(k);
        GrayCode(n, k - 1, list);
    }

    public static void Main()
    {
        Console.WriteLine(string.Join("", GrayCode(5)));
        /*
        for (int i = 1; i < 7; i++){
           //Console.WriteLine(string.Join("", GrayCode(i)));
        }
        */
    }
}