using System;

public class Program

{

    public static void DuplicateZeros(int[] arr) 

    {

        int len = arr.Length;

        for(int i = 0; i < len; i++)

        {

            if (arr[i] == 0)

            {

                int j;

                for (j = len - 2; j >= i + 1; j--)

                {

                    arr[j + 1] = arr[j];

                }

​

                arr[j + 1] = 0;

                i++;

            }

        }

    }

    public static void Main()

    {

        Console.WriteLine("UniLecs");

        // tests

        var arr1 = new int[] { 1, 0, 2, 3, 0, 4, 5, 0 };

        DuplicateZeros(arr1);

        Console.WriteLine(string.Join(",", arr1)); // [1, 0, 0, 2, 3, 0, 0, 4]

        var arr2 = new int[] { 1, 2, 3 };

        DuplicateZeros(arr2);

        Console.WriteLine(string.Join(",", arr2)); // [1, 2, 3]

    }

}