呵呵，昨天看了海老师的博客，今天也自己写了一个：
- go
- create proc pr_YangHui
- @n int --杨辉三角的层数，1~67
- as
- /* SQL实现显示杨辉三角 */
- /* 版本: 1.0 */
- /* 作者: dobear */
- /* 版权所有 */
- /* 2008.11.04 */
- begin
- set nocount on
- if @n<1 or @n>67
- return
- declare @t table(nid int identity(1,1), val bigint) --存储杨辉三角中的数字
- insert @t select top 80 1 from sysobjects a, sysobjects b
- declare @i int, @str varchar(4000), @nWidth int, @cSpace varchar(20)
- --计算数字的最大宽度,以便控制数字前面显示的空格
- set @i=1
- while @i<=@n
- begin
- update a set val=a.val+b.val
- from @t a join @t b on a.nid=b.nid+1 where a.nid<@i
- set @i=@i+1
- end
- select @nWidth = len(max(val))+1 from @t
- update @t set val=1 where nid<@i
- select @nWidth = @nWidth + @nWidth%2, @cSpace=space(@nWidth)
- --打印杨辉三角
- set @i=1
- while @i<=@n
- begin
- update a set val=a.val+b.val
- from @t a join @t b on a.nid=b.nid+1 where a.nid<@i
- set @str=''
- select @str=@str+right(@cSpace+cast(val as varchar), @nWidth) from @t where nid<=@i
- print space((@n-@i)*@nWidth/2)+@str
- set @i=@i+1
- end
- end
- go
- exec pr_YangHui 6
- /*
- 1
- 1 1
- 1 2 1
- 1 3 3 1
- 1 4 6 4 1
- 1 5 10 10 5 1
- */
- --drop proc pr_YangHui