TSql Challenge 56 结束了......所以我可以安全地怀疑那个
我试图在
下解决问题WITH CTE AS
(
SELECT
id ,
level ,
1 AS row ,
REPLICATE('X', POWER(3, level)) AS carpet
FROM TC56
UNION ALL
SELECT id ,
level ,
row + 1 ,
carpet
FROM CTE
WHERE Row < POWER(3, level)
)
SELECT
id
,row
,carpet
FROM CTE
ORDER BY id,row
但是输出与指定的输出不相符。我的输出在
之下id row carpet
1 1 X
2 1 XXX
2 2 XXX
2 3 XXX
3 1 XXXXXXXXX
3 2 XXXXXXXXX
3 3 XXXXXXXXX
3 4 XXXXXXXXX
3 5 XXXXXXXXX
3 6 XXXXXXXXX
3 7 XXXXXXXXX
3 8 XXXXXXXXX
3 9 XXXXXXXXX
问题在于我无法填补需要填充空格的位置
需要帮助
答案 0 :(得分：0)
这是一个可以扩展的解决方案，可以生成更大订单的Sierpinski地毯。目前它可以正确生成Sierpinski地毯，最高可达3 rd 。
通过'正确'我的意思是，可以为更大的订单模式生成所有必需的行，但是目前需要添加其他列（那些sortN个）以提供正确的行的排列。我已经添加了需要修改的注释。
WITH TC56 (id, level) AS (
SELECT 1, 0 UNION ALL
SELECT 2, 1 UNION ALL
SELECT 3, 2
),
x AS (
SELECT CAST('X' AS varchar(max)) AS x
),
rec_cte AS (
SELECT
x,
level = 0,
sort1 = 0,
sort2 = 0,
sort3 = 0
/* add new columns here */
FROM x
UNION ALL
SELECT
x = CAST(x.x + CASE TC56.level WHEN 1 THEN SPACE(LEN(x.x)) ELSE x.x END + x.x
AS varchar(max)),
level = x.level + 1,
sort1 = TC56.level,
sort2 = (TC56.level * 3 + x.sort1) % 3,
sort3 = ((TC56.level * 3 + x.sort1) * 3 + x.sort2) % 3
/* computations of the new columns' values follow the above pattern; e.g.
sort4 = (((TC56.level * 3 + x.sort1) * 3 + x.sort2) * 3 + x.sort3) % 3 */
FROM rec_cte x
CROSS JOIN TC56
WHERE x.level < 3 /* the necessary level to generate;
the last sortN's N number defines the maximum value
for which the pattern produced is guaranteed to be correct;
in this script the last sort column is sort3, so
the maximum 'supported' order is 3 */
)
SELECT * FROM rec_cte
ORDER BY level, sort1, sort2, sort3 /* add the new columns here */
结果如下：
x level sort1 sort2 sort3
------------------------------ ----------- ----------- ----------- -----------
X 0 0 0 0
XXX 1 0 0 0
X X 1 1 0 0
XXX 1 2 0 0
XXXXXXXXX 2 0 0 0
X XX XX X 2 0 1 0
XXXXXXXXX 2 0 2 0
XXX XXX 2 1 0 0
X X X X 2 1 1 0
XXX XXX 2 1 2 0
XXXXXXXXX 2 2 0 0
X XX XX X 2 2 1 0
XXXXXXXXX 2 2 2 0
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 0 0 0
X XX XX XX XX XX XX XX XX X 3 0 0 1
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 0 0 2
XXX XXXXXX XXXXXX XXX 3 0 1 0
X X X XX X X XX X X X 3 0 1 1
XXX XXXXXX XXXXXX XXX 3 0 1 2
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 0 2 0
X XX XX XX XX XX XX XX XX X 3 0 2 1
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 0 2 2
XXXXXXXXX XXXXXXXXX 3 1 0 0
X XX XX X X XX XX X 3 1 0 1
XXXXXXXXX XXXXXXXXX 3 1 0 2
XXX XXX XXX XXX 3 1 1 0
X X X X X X X X 3 1 1 1
XXX XXX XXX XXX 3 1 1 2
XXXXXXXXX XXXXXXXXX 3 1 2 0
X XX XX X X XX XX X 3 1 2 1
XXXXXXXXX XXXXXXXXX 3 1 2 2
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 2 0 0
X XX XX XX XX XX XX XX XX X 3 2 0 1
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 2 0 2
XXX XXXXXX XXXXXX XXX 3 2 1 0
X X X XX X X XX X X X 3 2 1 1
XXX XXXXXX XXXXXX XXX 3 2 1 2
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 2 2 0
X XX XX XX XX XX XX XX XX X 3 2 2 1
XXXXXXXXXXXXXXXXXXXXXXXXXXX 3 2 2 2