using System;

​

public class Program

{

    static void stars(int count)

    {

        for (int g = 0; g < count; ++g)

            Console.Write("*");

    }

​

    static void spaces(int count)

    {

        for (int g = 0; g < count; ++g)

            Console.Write(" ");

    }

​

    public static void Main(string[] args)

    {

        char ch;

        Console.WriteLine("Enter an alphabet");

        ch = Convert.ToChar(Console.ReadLine());

​

        switch (Char.ToLower(ch))

        {

            case 'a':

​

​

​

                Console.Write("first star pattern");

                Console.ReadLine();

                int nums;

                Console.Write("Enter number of rows\n");

                nums = int.Parse(Console.ReadLine());

                for (int row = nums; row >= 1; --row)

                {

                    for (int col = 1; col <= row; ++col)

                    {

                        Console.Write("*");

                    }

​

                    Console.WriteLine();

                }

                break;

            case 'b':

​

                Console.Write("second star pattern");

                Console.ReadLine();

                int x;

                Console.Write("Enter number of rows\n");

                x = int.Parse(Console.ReadLine());

                for (int row = 1; row <= x; ++row)

                {

                    for (int col = 1; col <= row; ++col)

                    {

                        Console.Write("*");

                    }

​

                    Console.WriteLine();

                }

                break;

​

            case 'c':

​

                Console.Write("third star pattern");

                Console.ReadLine();

                int number, i, k, count = 1;

                Console.Write("Enter number of rows\n");

                number = int.Parse(Console.ReadLine());

                count = number - 1;

                for (k = 1; k <= number; k++)

                {

                    for (i = 1; i <= count; i++)

                        Console.Write(" ");

                    count--;

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

                        Console.Write("*");

                    Console.WriteLine();

                }

                count = 1;

                for (k = 1; k <= number - 1; k++)

                {

                    for (i = 1; i <= count; i++)

                        Console.Write(" ");

                    count++;

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

                        Console.Write("*");

                    Console.WriteLine();

                }

                Console.ReadLine();

                break;

​

            case 'd':

​

                Console.Write("fourth star pattern");

                Console.ReadLine();

                int y;

                Console.Write("Enter number of rows\n");

                y = int.Parse(Console.ReadLine());

​

                int val = y;

                int m, j, n;

                for (m = 1; m <= y; m++)

                {

                    for (j = 1; j <= y - m; j++)

                    {

                        Console.Write(" ");

                    }

                    for (n = 1; n <= m; n++)

                    {

                        Console.Write("*");

                    }

                    Console.WriteLine("");

                }

                Console.ReadLine();

                break;

​

            case 'e':

​

                Console.Write("five star pattern");

                Console.ReadLine();

​

​

                int numd = 8;

​

                for (int v = 0; v < numd; ++v)

                {

                    for (int w = 0; w <= v; ++w)

                    {

                        Console.Write("*");

                    }

​

                    if (v != numd - 1)

                    {

                        Console.Write(" ");

                    }

                    else

                    {

                        Console.Write(" * ");

                    }

                    for (int w = 0; w <= v; ++w)

                    {

                        Console.Write("*");

                    }

​

                    Console.WriteLine();

                }

                break;

            case 'f':

​

                Console.Write("sixth star pattern");

                Console.ReadLine();

​

                int numb = 7;

​

                for (int q = 0; q < numb; q++)

                {

                    if (q == 0 || q == 6)

                    {

                        for (int r = 0; r < numb; r++)

                        {

                            Console.Write("*");

                        }

                        Console.WriteLine();

                    }

                    if (q >= 1 && q <= 5)

                    {

                        for (int r = 0; r < numb; r++)

                        {

                            if (r == 0 || r == 6)

                            {

                                Console.Write("*");

                            }

                            else if (r >= 1 && r <= 5)

                            {

                                Console.Write(" ");

                            }

                        }

                        Console.WriteLine();

                    }

                }

                break;

​

            case 'g':

​

                Console.Write("seventh star pattern");

                Console.ReadLine();

                int s;

                Console.Write("Enter number of rows\n");

                s = int.Parse(Console.ReadLine());

​

                int f = s;

​

                for (int g = 0; g < s; ++g)

                {

                    stars(g + 1);

                    spaces(s - g - 1);

                    stars(s - g + 1);

                    spaces(2 * g);

                    stars(s - g);

                    spaces(s - g - 1);

                    stars(g + 1);

​

                    Console.WriteLine();

                }

                break;

​

            default:

                Console.WriteLine("no pattern is availaible");

                Console.ReadLine();

                break;

        }

    }

}

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