如何用C#实现排列组合?

Question

see (didn't verify, so I have no idea if they work, :-))Combinatorial algorithms in C#
http://www.codeproject.com/csharp/combinatorial_in_csharp.asp(also see the whole thread)
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=27o2rk%24m5g%40crcnis1.unl.edu

Answer 1

同上，我也只有这个笨办法 
先求长度，然后在进行判断但不是对字符进行判断，转换为INT在进行判断

Answer 2

http://www.cstc.net.cn/docs/docs.php?id=140http://www.programfan.com/showarticle.asp?id=2237

Answer 3

http://www.yuguo.com/Computer/cxsj/20040104/220836.htm