用C#写的全排列

         using System;
        using System.Collections.Generic;
        using System.Linq;
        using System.Text;
        namespace perm
        {
            class Program
            {
                static void permlist(int[] listdata, int k, int m)
                    {
                        if (k == m)
                       {
                            for (int i = 0; i <= m; i++) System.Console.Write(listdata[i]);
                            Console.WriteLine();
                        }
                        else
                            for (int i = k; i <= m; i++)
                            {
                                Swap(ref listdata[k],ref listdata[i]);
                                permlist(listdata, k + 1, m);
                                Swap(ref listdata[k],ref listdata[i]);
                            }
                    }
                    static void Swap(ref int a,ref int b)
                    {
                        int temp = a; a = b; b = temp;
                    }
                static void Main(string[] args)
                {
                    int[] listdata = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
                    permlist(listdata, 0, 3);
                }
            }
        }