using System;

public class Program

{

    public static void Main()

    {

        int n=5, i, j, k;

        int cn=1;

        for(i=1; i<=n*2-1; i++)

        {

            for(j=cn; j<n ; j++)

            {

                Console.Write(" ");

            }

            for(k=1; k<=cn*2-1; k++)

            {

                Console.Write("*");

            }

            if(i<n)

            {

                cn++;

            }

            else

            {

                cn--;

            }

            Console.Write("\n");

        }

    }

}

​

​

​

​

​

​

​

/*

    *

   **

  ***

 ****

*****

 ****

  ***

   **

    *

​

*/

​

​

​

​