using System;

using System.Collections.Generic;

​

public static class Program

{

    public static void Main(string[] _args)

    {

       PrintPattern(4);

    }

    static void PrintPattern(int num, char c = '*')

    {

        var list = new List<char>();

        for(int i = 1; i <= num; i++)

        {

            list.Add(c);

            Console.Write(String.Join(" ", list) + "\r\n");

        }

    }

}