给出任意几个字符，列出所有的排列组合。
方法一：
public static List<List<string>> zuhe(List<string> arr)
{
List<List<string>> rtn;
if (arr.Count == 1)
{
rtn = new List<List<string>>(1);
rtn.Add(arr);
return rtn;
}
rtn = new List<List<string>>();
for (int i = 0; i < arr.Count; i++)
{
List<string> tmp = new List<string>(arr.Count);
tmp.AddRange(arr);
string prefix = tmp[i];
tmp.RemoveAt(i);
List<List<string>> temp = zuhe(tmp);
for (int j = 0; j < temp.Count; j++)
temp[j].Insert(0, prefix);
rtn.AddRange(temp);
}
return rtn;
}
方法二：
using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.IO;
namespace Date1219
{
class NumArrangement
{
/**//// <summary>
/// 实现任意输入字符串的全排列
/// </summary>
/// <param name="str"></param>
/// <returns></returns>
public ArrayList Arrange(string str)
{
ArrayList list = new ArrayList();
for (int i = 0; i < str.Length; i++)
{
list = InsertValue(str[i].ToString(), list);
}
return list;
}
public ArrayList InsertValue(string str, ArrayList list)
{
int rowct = list.Count;
int rayct;
ArrayList list2 = new ArrayList();
if (list.Count >0)
{
ArrayList temp = (ArrayList)list[0];
rayct = temp.Count;
for (int i = 0; i < rowct; i++)
{
for (int j = 0; j < rayct+1; j++)
{
ArrayList list4 = new ArrayList((ArrayList)list[i]);//Arraylist 的深度复制
list4.Insert(j, str);
list2.Add(list4);
}
}
}
else
{
rayct = 0;
list.Add(str);
list2.Add(list);
}
return list2;
}
//打印
public void PrintList(ArrayList list)
{
for (int i = 0; i < list.Count; i++)
{
ArrayList list2 = (ArrayList)list[i];
for (int j = 0; j < list2.Count; j++)
{
Console.Write(list2[j] + " ");
}
Console.WriteLine();
}
Console.ReadLine();
}
}
class Test
{
public static void Main(String[] args)
{
NumArrangement na = new NumArrangement();
//交互界面
Console.WriteLine("Input your Num:");
string input = Console.ReadLine();
Console.WriteLine("Your Number Arrangement:");
ArrayList list = na.Arrange(input);
na.PrintList(list);
}
}
}