yeah，组合的也出来了，再一起发一个
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication32
{
class Program
{
static int s = 0;
static void Main(string[] args)
{
Console.WriteLine("输入要排列的数字");
string strs = Console.ReadLine();
List<string> list = new List<string>();
int a = 5;
Console.WriteLine("输入要排列的个数");
int b = Int32.Parse(Console.ReadLine());
Compages(strs, "", list, b);
Console.WriteLine("_______________________________________");
for (int i = 0; i < list.Count; i++)
{
Console.WriteLine(list[i]);
}
Console.WriteLine("共："+s+"个");
Console.Read();
}
/// <summary>
/// 数学排列算法P(N,M)
/// </summary>
/// <param name="num">需要排列的字符串</param>
/// <param name="curnum"></param>
/// <param name="list">排列出的字符串集合</param>
/// <param name="n">需要排列的个数</param>
public static void Compute( string num,string curnum,List<string> list,int n)
{
for (int i = 0; i < num.Length; i++)
{
curnum+= num[i].ToString();
if (curnum.Length == n)
{
list.Add(curnum);
s++;
}
else
{
string temp = num.Remove(i, 1);
Compute(temp,curnum,list,n);
}
curnum = curnum.Remove(curnum.Length - 1, 1);
}
}
/// <summary>
/// 数学组合算法 C(n,m)
/// </summary>
/// <param name="num">要组合�
