经典项链题

基本题:

有10种不同颜色的珠子各2颗. 现要做成一条项链. 问有多少种不同的做法.

扩展版:

1. 将10推广到任意的n.
2. 将2推广到任意的k.

所有跟帖： 

• 回复：经典项链题 -Allegretto- ♀ (50 bytes) () 10/04/2003 postreply 23:55:00

• No. Far not that easy. -火球魔法- ♀ (0 bytes) () 10/05/2003 postreply 02:03:00

• 回复：No. Far not that easy. -Allegretto- ♀ (546 bytes) () 10/05/2003 postreply 12:56:00

• this has problem -NoMath- ♀ (387 bytes) () 10/06/2003 postreply 12:37:00

• 跟我的答案一样 -作者公布答案看看- ♀ (0 bytes) () 10/05/2003 postreply 10:55:00

• My comments stays the same. -火球魔法- ♀ (201 bytes) () 10/05/2003 postreply 20:29:00

• 回复：经典项链题 -bbdebbie- ♀ (13 bytes) () 10/05/2003 postreply 20:33:00

• 回复：经典项链题 -yaluzangbu- ♀ (67 bytes) () 10/06/2003 postreply 15:42:00

• 回复：回复：经典项链题 -NLogN- ♀ (328 bytes) () 10/08/2003 postreply 23:20:00

• 回复：回复：经典项链题 -NLogN- ♀ (90 bytes) () 10/09/2003 postreply 22:34:00

• 回复：回复：回复：经典项链题 -yaluzangbu- ♀ (84 bytes) () 10/09/2003 postreply 15:28:00

• 回复：经典项链题 -yaluzangbu- ♀ (338 bytes) () 10/06/2003 postreply 18:32:00

• This is the standard answer. -火球魔法- ♀ (0 bytes) () 10/07/2003 postreply 00:14:00

• 雅鲁藏布, 猛啊. -火球魔法- ♀ (0 bytes) () 10/07/2003 postreply 00:18:00

• 回复：经典项链题 -野菜花- ♀ (32 bytes) () 10/08/2003 postreply 08:53:00

• 回复：经典项链题 -jadeqq- ♀ (25 bytes) () 10/08/2003 postreply 13:53:00