using System;
using System.Collections.Generic;
using System.Text;
namespace AVG
{
class Program
{
static void Main(string[] args)
{
double [] myArray = new double[10];
double sum = 0;
double avg = 0;
Console.WriteLine("请输入十个数");
for (int i = 0; i < 10; i++)
{
myArray[i] = Convert.ToDouble(Console.ReadLine());
sum += myArray[i];
}
avg = sum / 10;
Console.WriteLine("十个数的平均数为"+avg);
Console.ReadLine();
}
}
}

using System;
namespace HelloWorldApplication
{
class Program
    {
        static void Main(string[] args)
        {
            int[] change = { 23, 11, 44, 77, 7 };
            int length = change.Length;//得到数组的长度
            int i;
            Console.WriteLine("原数组排序:");
            for (i = 0; i < length; i++)//循环输出排序前的值
            {
                Console.WriteLine("{0}", change[i]);
            }
            //下面是Array.Sort升序排列
            Array.Sort(change);
            Console.WriteLine("数组升序后:");
            for (i = 0; i < length; i++)
            {
                Console.WriteLine("{0}", change[i]);//循环输出Array.Srot升序排列结果
            }
            //下面是Array.Reverse降序排列后
            Array.Reverse(change);
            Console.WriteLine("数组降序后:");
            for (i = 0; i < length; i++)
            {
                Console.WriteLine("{0}", change[i]);//循环输出Array.Reverse降序排列结果
            }
            Console.ReadKey();
        }
    }
	
}

using System;

namespace CalculatorApplication
{
    class NumberManipulator
    {
		public int num;
 	public int factorial(int aVal)
        {
            int sum = 0;
            if (aVal == 0)
            {
                return 0;
            }
            if (aVal == 1)
            {
                return sum = 1;
            }
            else if (aVal == 2)
            {
                return sum = 2;
            }
            else
            {
                int[] Fibo = new int[aVal];
                for (int i = 0; i < aVal; i++)
                {
                    Fibo[0] = 1;
                    Fibo[1] = 1;
                    for (int j = 3; j <= aVal; j++)
                    {
                        Fibo[j - 1] = Fibo[j - 2] + Fibo[j - 3];
                    }
                    sum = sum + Fibo[i];
                }
            }
            return sum;
        }

		static void Main(string[] args)
        {
            NumberManipulator r = new NumberManipulator();
 			r.num = 100;
            Console.WriteLine("斐波那契前100项的结果为：{0}",  r.factorial(r.num));
            Console.ReadLine();

        }
		
    }
	
	
}

using System;

namespace CalculatorApplication
{
    class NumberManipulator
    {
  public int num1;
  public int num2;
        public int factorial(int num)
        {
            int result;

            if (num == 1)
            {
                return 1;
            }
            else
            {
                result = factorial(num - 1) * num;
                return result;
            }
        }
   
        static void Main(string[] args)
        {
            NumberManipulator r = new NumberManipulator();
 
            //调用 factorial 方法
           r.num1 = 10;
           r.num2 = 4;
           int k;
           k = r.num1 - r.num2;
            Console.WriteLine("组合C(10,4)的结果为：{0}",  r.factorial(r.num1)/ r.factorial(r.num2)/ r.factorial(k));
            Console.ReadLine();

        }
    }
}