你能用算术运算符+、-、*、/ 及左右括号使3、4、5、6的结果等于28吗？每个数字只能用一次，每个算术运算符和括号也只能用一次

[lg3605119]

如题
高手最好能写成通用的，就是数字和结果改变也能使用。期待解答！

[-狙击手-]

[conan304]

太牛了，佩服

[belsonB5]

帮我看看这个问题好不好！谢谢了！

http://topic.csdn.net/u/20090408/15/280de90a-87f2-440d-8049-72b138d0a563.html

[lg3605119]

期待简单点的答案

[lg3605119]

期待高手继续解答

[you_tube]

[Quote=引用 9 楼 liangCK 的回复:]
太牛了吧..
[/Quote].

[dj3688]

牛

[lg3605119]

没人解答 自己UP下

[lg3605119]

蓉儿 树上的鸟儿辛苦了

[lg3605119]

偶已经加分到100 这是我发贴的最高分

[htl258_Tony]

牛人.

[等不到来世]

50分有点少

[lg3605119]

解答就加分

[claro]

帮顶

[等不到来世]

写了一天，累死了。
用了2－3个临时表存储中间结果，
尽量去除了不必要的数据，
最大的一个也控制在千行左右，
效率应该还是比较高的。

if object_id('myCal','P') is not null
	drop proc myCal
go
create proc myCal
	@a dec(18,3),
	@b dec(18,3),
	@c dec(18,3),
	@d dec(18,3),
	@result int=24
as
	set nocount on
	--1.参数检查与初始化
	if isnull(floor(@a),-1)<isnull(@a,0) or isnull(floor(@b),-1)<isnull(@b,0) 
	or isnull(floor(@c),-1)<isnull(@c,0) or isnull(floor(@d),-1)<isnull(@d,0)
	begin
		print '请输入合法参数(正整数)'
		return
	end

	select id=identity(int),val into #val --数据表
	from(select @a val union all select @b union all select @c union all select @d) t

	select id=identity(int),sig into #sign --符号表
	from(select '+' sig union all select '-' union all select '*' union all select '/') t

	--2.先取两个数的所有有效组合
	select  a.id aid,s.id s1,b.id bid,a.val a,b.val b
			,formula=rtrim(a.val)+s.sig+rtrim(b.val)
			,result=case s.id when 1 then a.val+b.val when 2 then a.val-b.val when 3 then a.val*b.val when 4 then a.val/b.val end
	into #1
	from #val a,#sign s,#val b
	where (s.id in(1,3) and a.id<b.id) or (s.id=2 and a.id<>b.id and a.val>=b.val) or (s.id=4 and a.id<>b.id)
	--select * from #1

	--3.加入第三个数
	select a.aid,a.s1,a.bid,s.id s2,b.id cid,b.val c
			,formula=case when a.s1 in(1,2) and s.id in(3,4) then '('+a.formula+')' else a.formula end + s.sig + rtrim(b.val)
			,result=case s.id when 1 then a.result+b.val when 2 then a.result-b.val when 3 then a.result*b.val when 4 then a.result/b.val end
	into #2
	from #1 a,#sign s,#val b
	where a.aid<>b.id and a.bid<>b.id and (s.id<>2 or s.id=2 and a.result>=b.val)
	union all
	select a.aid,a.s1,a.bid,s.id s2,b.id cid,b.val c
			,formula=rtrim(b.val) + s.sig + '('+a.formula+')'
			,result=case s.id when 2 then b.val-a.result when 4 then b.val/a.result end
	from #1 a,#sign s,#val b
	where a.aid<>b.id and a.bid<>b.id and (s.id=2 and a.result<b.val or s.id=4 and a.result>0)
	--select * from #2

	--4.加入第四个数
	select formula=case when a.s2 in (1,2) and s.id in(3,4) then '('+a.formula+')' else a.formula end + s.sig + rtrim(b.val)
			,result=case s.id when 1 then a.result+b.val when 2 then a.result-b.val when 3 then a.result*b.val when 4 then a.result/b.val end
	into #3
	from #2 a,#sign s,#val b
	where a.aid<>b.id and a.bid<>b.id and a.cid<>b.id and (s.id<>2 or s.id=2 and a.result>=b.val)
	union all
	select formula=rtrim(b.val) + s.sig + '('+a.formula+')'
			,result=case s.id when 2 then b.val-a.result when 4 then b.val/a.result end
	from #2 a,#sign s,#val b
	where a.aid<>b.id and a.bid<>b.id and a.cid<>b.id and (s.id=2 and a.result<b.val or s.id=4 and a.result>0)

	--5.选取结果并格式化
	select  distinct formula=replace(formula,'.000',''),result=@result
	from #3
	where result=@result
go

[等不到来世]

--使用示例：
exec myCal 3,4,5,6,28
/*
formula		result
-----------------
(6/3+5)*4	28
*/

exec myCal 5,5,5,1
/*
formula		result
-----------------
(5-(1/5))*5	24
*/

exec myCal -1,0,1.2,5
/*
请输入合法参数(正整数)
*/

[等不到来世]

参数检查部分不是很完善，不过无关紧要，不想写那么鲁棒

[等不到来世]

看了一下LZ的题目，居然还有这个要求：每个符号只能用一次。。。
那还得改进一下，不想改了

[chuifengde]

CREATE PROC getll(@sql1 nVARCHAR(20),@sql2 nVARCHAR(20),@sql3 nVARCHAR(20),@sql4 nVARCHAR(20),@sql5 nvarchar(20),@N INT,@r nvarchar(20) OUT )
 AS 
 	declare @sql nvarchar(500)
 	DECLARE @x INT ,@y INT, @c INT ,@d INT ,@e int
 	
 	SET @sql=N'select @x='+@sql1+',@y='+@sql2+',@c='+@sql3+',@d='+@sql4 +',@e='+@sql5		
 	exec sp_executesql @sql,N'@x int out,@y int out ,@c int out ,@d int out,@e int out',@x OUT,@y OUT ,@c OUT  ,@d OUT ,@e OUT  	
 	IF @x=@n 
 		SET @r=@sql1
 	ELSE IF @y =@n 	 
 		SET @r=@sql2
 	ELSE IF @c=@n 
 		SET @r=@sql3
 	ELSE IF @d=@N
 		SET @r=@sql4
 	ELSE IF @e=@n 
 		SET @r=@sql5
 	ELSE 
 		SET @r=''
 	
 	RETURN 
 	 
GO 
DECLARE @a TABLE(a VARCHAR(2))
INSERT @a SELECT '3'
UNION ALL SELECT '4'
UNION ALL SELECT '5'
UNION ALL SELECT '6'
DECLARE @b TABLE(a VARCHAR(2))
INSERT @b SELECT '+'
UNION ALL SELECT '-'
UNION ALL SELECT '*'
UNION ALL SELECT '/'

DECLARE @s TABLE(a VARCHAR(100),b VARCHAR(100),c VARCHAR(100),d VARCHAR(100),e VARCHAR(100))
INSERT @s 
SELECT 	x+a.a+a1.a+b.a+y+a2.a+c.a+a3.a+d.a a,
	x+a.a+a1.a+b.a+a2.a+c.a+y+a3.a+d.a b,
	a.a+a1.a+x+b.a+a2.a+c.a+y+a3.a+d.a c,
	a.a+a1.a+x+b.a+a2.a+c.a+a3.a+d.a+y d,
	a.a+a1.a+b.a+a2.a+x+c.a+a3.a+d.a+y e
FROM @a a,@a b,@a c,@a d,
 @b a1,@b a2,@b a3,@b a4,(SELECT '(' x) xx, (SELECT ')' y)yy
WHERE a.a<>b.a AND a.a<>c.a AND a.a<>d.a AND b.a<>c.a AND b.a<>d.a AND c.a<>d.a
and a1.a<>a2.a AND a1.a<>a3.a AND a1.a<>a4.a 
   AND a2.a<>a3.a AND a2.a<>a4.a 
   AND a3.a<>a4.a 
   
DECLARE @aa VARCHAR(20),@bb VARCHAR(20),@cc  VARCHAR(20),@dd  VARCHAR(20),@ee  VARCHAR(20)
DECLARE @l VARCHAR(200)
DECLARE @r VARCHAR(20)    
 
DECLARE @n INT 
SET @n=24
DECLARE cur CURSOR FOR SELECT a,b,c,d,e FROM @s 
OPEN cur  
FETCH NEXT from cur INTO @aa ,@bb ,@cc ,@dd, @ee 
WHILE @@FETCH_STATUS=0
BEGIN
	EXEC getll @aa,@bb,@cc,@dd,@ee,@N,@l OUT 
	IF @l<>'' 
		PRINT @l
	FETCH NEXT FROM cur INTO @aa ,@bb ,@cc ,@dd, @ee
END 
CLOSE CUR
DEALLOCATE cur

[chuifengde]

--result/*
(3/5)+6*4
(3+5/4)*6
(3+5-4)*6
(3/5)+4*6
(3-4+5)*6
(4*6)-3/5
(4*6)+3/5
(4+3/5)*6
(4-3/5)*6
4*(3/5+6)
(5-4/3)*6
(5-4+3)*6
(5/4+3)*6
(5+3-4)*6
6*(5-4/3)
6*(5/4+3)
6*(5-4+3)
6*(5+3-4)
(6+3/5)*4
(6-3/5)*4
6*(3/5+4)
6*(3+5/4)
6*(3+5-4)
(6*4)-3/5
(6*4)+3/5
6*(3-4+5)
*/