C# 输出用“*”组成的菱形
 
using System;
using System.Collections.Generic;
using System.Text;
namespace ConsoleShui
{
    class Program
    {
        /**********************输出菱形**********************/
        static void Main(string[] args)
        {
            int i;
            int j;
            int k;
            for (i = 0; i <=10; i++)                /*输出上面10行的*号*/
            {
                for(j = 0; j <10 - i; j++)
                        Console.Write("  ");               /*输出*前面的空格*/
                for (k = 0; k <2 * i-1; k++)
                    Console.Write("*");          /*输出一行（若干个）*号*/
                Console.WriteLine();
            }
            for (i = 0; i <= 9; i++)                 /*输出下面9行*号*/
            {
                for (j = 0; j<=i;j++)
                    Console.Write("  ");              /*输出*前面的空格*/
                for (k = 0; k<17-2 * i; k++)
                    Console.Write("*");          /*输出一行（若干个）*号*/
                Console.WriteLine();
            }
            Console.Read();
        }
    }
}