C# 水仙花数

using System;
using System.Collections.Generic;
using System.Text;

namespace NarcissusNumber
{
    class Program
    {
       public static void Main(string[] args)
        {
            int a;
            string s;
            do
            {
                Console.WriteLine("3----找出三位数所有的水仙花数！");
                Console.WriteLine("4----找出四位数所有的水仙花数！");
                Console.WriteLine("5----找出五位数所有的水仙花数！");
                Console.WriteLine("34---你选择找出三、四位数的水仙花数！");
                Console.WriteLine("45---你选择找出四、五位数的水仙花数！");
                Console.WriteLine("35---你选择找出三、四、五位数的水仙花数！");
                Console.WriteLine("0----退出");
                Console.Write("请选择操作（0，3，4，5, 34, 45, 35）：");
                s= Console.ReadLine();
                a = int.Parse(s);
                switch (a)
                {
                    case 0:Console.WriteLine("你选择退出！");
                        break;
                    case 3:Console.WriteLine("你选择找出三位数的水仙花数！");
                           Funtion(a);
                        break;
                    case 4:Console.WriteLine("你选择找出四位数的水仙花数！");
                        Funtion(a);
                        break;
                    case 5:Console.WriteLine("你选择找出五位数的水仙花数！");
                        Funtion(a);
                        break;
                    case 34: Console.WriteLine("你选择找出三、四位数的水仙花数！");
                        Funtion(a);
                        break;
                    case 45: Console.WriteLine("你选择找出四、五位数的水仙花数！");
                        Funtion(a);
                        break;
                    case 35: Console.WriteLine("你选择找出三、四、五位数的水仙花数！");
                        Funtion(a);
                        break;
                    default: Console.WriteLine("你的输入是不合理的！请重先选择！");
                        break;
                }
                Console.WriteLine();
               // Console.Clear();              /*清屏*/
            } while (a!=0);  
        }
        /*******************输出水仙花数的算法*******************************/
        static int Funtion(int s)    
        {
            int i;
            int j;
            int k;
            int n;
            int m;
            int l;
            if (s==3)                  /*输出100-999的水仙花数*/
            {
                for(n=100;n<999;n++)
                {
                    i = n / 100;
                    j = n / 10 - i * 10;
                    k = n % 10;
                    if (n==Recursion(i,s) + Recursion(j,s) + Recursion(k,s))
                        Console.WriteLine(n);
                }
            }
            else if (s == 4)               /*输出1000-9999的水仙花数*/
            {
                for (n = 1000; n <= 9999; n++)
                {
                    i = n / 1000;
                    j = n / 100 - i * 10;
                    k = n / 10 - i * 100 - j * 10;
                    l = n % 10;
                    if (n == Recursion(i, s) + Recursion(j, s) + Recursion(k, s) + Recursion(l, s))
                        Console.WriteLine(n);
                }
            }
            else if(s==5)                     /*输出10000-99999的水仙花数*/
            {
                for (n = 10000; n <= 99999; n++)
                {
                    i = n / 10000;
                    j = n / 1000 - i * 10;
                    k = n / 100 - i * 100 - j * 10;
                    l = n / 10 - i * 1000 - j * 100 - k * 10;
                    m = n % 10;
                    if (n == Recursion(i, s) + Recursion(j, s) + Recursion(k, s) + Recursion(l, s) + Recursion(m, s))
                        Console.WriteLine(n);
                }
            }
            else if (s ==34)                 /*输出100-9999的水仙花数*/
            {
                for (n = 100; n <= 9999; n++)
                {
                    i = n / 1000;
                    j = n / 100 - i * 10;
                    k = n / 10 - i * 100 - j * 10;
                    l = n % 10;
                    if (i != 0 && n==Recursion(i, 4) + Recursion(j, 4) + Recursion(k, 4) + Recursion(l, 4))
                        Console.WriteLine(n);
                    if (n== Recursion(j, 3) + Recursion(k, 3) + Recursion(l, 3))
                        Console.WriteLine(n);
                }
            }
            else if(s == 45)                 /*输出1000-9999的水仙花水*/
            {
                for (n = 1000; n <= 99999; n++)
                {
                    i = n / 10000;
                    j = n / 1000 - i * 10;
                    k = n / 100 - i * 100 - j * 10;
                    l = n / 10 - i * 1000 - j * 100 - k * 10;
                    m = n % 10;
                    if (i != 0 && n == Recursion(i, 5) + Recursion(j, 5) + Recursion(k, 5) + Recursion(l, 5) + Recursion(m, 5))
                        Console.WriteLine(n);
                    if (n == Recursion(j, 4) + Recursion(k, 4) + Recursion(l, 4) + Recursion(m, 4))
                        Console.WriteLine(n);
                    
                }
            }
            else                         /* 输出100-99999的水仙花数*/
            {
               for (n = 100; n <= 99999; n++)
                {
                    i = n / 10000;
                    j = n / 1000 - i * 10;
                    k = n / 100 - i * 100 - j * 10;
                    l = n / 10 - i * 1000 - j * 100 - k * 10;
                    m = n % 10;
                    if (i != 0 && n == Recursion(i, 5) + Recursion(j, 5) + Recursion(k, 5) + Recursion(l, 5) + Recursion(m, 5))
                        Console.WriteLine(n);
                    else if (j != 0 && n == Recursion(j, 4) + Recursion(k, 4) + Recursion(l, 4) + Recursion(m, 4))
                        Console.WriteLine(n);
                    else if (n== Recursion(k, 3) + Recursion(l, 3) + Recursion(m, 3))
                        Console.WriteLine(n);
                }
            }
            return 0;
        }
        /*********************用递归求数n的k次方*******************************/
        static int Recursion(int n,int k)
        {
            int m;
            if (k == 1) return n;
            else
            {
                 m=n*Recursion(n,k-1);
            }
            return m;
        }
    }
}