February 19, 2018 at 10:29 pm
Comments posted to this topic are about the item Solve Sudoku with T-SQL - Part 1
February 20, 2018 at 12:49 am
Interesting article - thank you - I couldn't find the code download link .. is it me or the website ?
KR Geoff Johns
February 20, 2018 at 1:11 am
Geoff Johns - Tuesday, February 20, 2018 12:49 AMInteresting article - thank you - I couldn't find the code download link .. is it me or the website ?
KR Geoff Johns
Hi Geoff
It appears not to be there so have sent to admin so hopefully they can re-add otherwise is attached for your reference
Hope you enjoy - next part of article includes optimisation and is much much faster!!!
Thanks for mentioning
Cheers
Bevan
February 20, 2018 at 1:12 am
bevanward - Tuesday, February 20, 2018 1:11 AMGeoff Johns - Tuesday, February 20, 2018 12:49 AMInteresting article - thank you - I couldn't find the code download link .. is it me or the website ?
KR Geoff JohnsHi Geoff
It appears not to be there so have sent to admin so hopefully they can re-add otherwise is attached for your referenceHope you enjoy - next part of article includes optimisation and is much much faster!!!
Thanks for mentioning
Cheers
Bevan
use tempdb
go
if object_id('dbo.sp_sudoku_solve_simple') is not null
drop procedure dbo.sp_sudoku_solve_simple
go
create procedure dbo.sp_sudoku_solve_simple @PuzzleIn char(81) as
/*
Author: Bevan Ward
Date: 21-Jan-2018
Purpose: The following stored procedure solves Sudoku puzzles via a single select statement. It is NOT intended to be used for puzzles harder than absolute beginner level.
A method showing a highly optimised approach will be provided next article!
Copyright: Bevan Ward
Syntax: exec dbo.sp_sudoku_solve_simple @PuzzleIn = '<81 character puzzle - 0 represents blank cell>'
Example: exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
-- Set of 10 simple puzzles
exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
exec sp_sudoku_solve_simple '600050002010702040000346000084000590509000207032000480000165000020407060300090004'
exec sp_sudoku_solve_simple '800259004040010070000407000302080506580302091607040302000504000060090020700826009'
exec sp_sudoku_solve_simple '703200104054019380000500000070000805060000030308000090000001000035920460407008903'
exec sp_sudoku_solve_simple '700200008020405070004080300060508037009000800180607020001070600050903010600004003'
exec sp_sudoku_solve_simple '000400000004063200809000503090030005040658030600010070901000804005840100000007000'
exec sp_sudoku_solve_simple '007400803000206001000085700026000039004000100370000680908620000000108000630009200'
exec sp_sudoku_solve_simple '019600430000098000002005100098074001020000080700850620007500800000730000056001970'
exec sp_sudoku_solve_simple '280060079100007006070930080907000605008000700040000090090025060800600002650010047'
exec sp_sudoku_solve_simple '107608209840050036000000000300106004060000090200305007000000000430060052508209301'
*/
set nocount off
declare @sql varchar(max) =''
declare @Select varchar(max) =''
declare @Exclusion varchar(max) =''
declare @PuzzleSolution char(81)
/* 81 long number table of row, column and block mapping */
create table #tGrid (CoordinateID int, RowNum int, ColumnNum int, BlockNum int)
create clustered index IDX01_tGrid on #tGrid (CoordinateID)
/* output solutions - write to table so can display as 9x9 grids in final output */
create table #solutions (SolutionID int, [1] char(1), [2] char(1), [3] char(1), [4] char(1), [5] char(1), [6] char(1), [7] char(1), [8] char(1), [9] char(1), [10] char(1), [11] char(1), [12] char(1), [13] char(1), [14] char(1), [15] char(1), [16] char(1), [17] char(1), [18] char(1), [19] char(1), [20] char(1), [21] char(1), [22] char(1), [23] char(1), [24] char(1), [25] char(1), [26] char(1), [27] char(1), [28] char(1), [29] char(1), [30] char(1), [31] char(1), [32] char(1), [33] char(1), [34] char(1), [35] char(1), [36] char(1), [37] char(1), [38] char(1), [39] char(1), [40] char(1), [41] char(1), [42] char(1), [43] char(1), [44] char(1), [45] char(1), [46] char(1), [47] char(1), [48] char(1), [49] char(1), [50] char(1), [51] char(1), [52] char(1), [53] char(1), [54] char(1), [55] char(1), [56] char(1), [57] char(1), [58] char(1), [59] char(1), [60] char(1), [61] char(1), [62] char(1), [63] char(1), [64] char(1), [65] char(1), [66] char(1), [67] char(1), [68] char(1), [69] char(1), [70] char(1), [71] char(1), [72] char(1), [73] char(1), [74] char(1), [75] char(1), [76] char(1), [77] char(1), [78] char(1), [79] char(1), [80] char(1), [81] char(1))
/* Fixed puzzle values */
create table #tFixed (CoordinateID int, Value int)
/* options */
create table #tOption (CoordinateID int, Value int)
create clustered index IDX01_tOption on #tOption (CoordinateID)
/* Construct references for row, column and block CoordinateID logic */
insert into #tGrid (CoordinateID, RowNum, ColumnNum, BlockNum) values (1,1,1,1),(2,1,2,1),(3,1,3,1),(4,1,4,2),(5,1,5,2),(6,1,6,2),(7,1,7,3),(8,1,8,3),(9,1,9,3),(10,2,1,1),(11,2,2,1),(12,2,3,1),(13,2,4,2),(14,2,5,2),(15,2,6,2),(16,2,7,3),(17,2,8,3),(18,2,9,3),(19,3,1,1),(20,3,2,1),(21,3,3,1),(22,3,4,2),(23,3,5,2),(24,3,6,2),(25,3,7,3),(26,3,8,3),(27,3,9,3),(28,4,1,4),(29,4,2,4),(30,4,3,4),(31,4,4,5),(32,4,5,5),(33,4,6,5),(34,4,7,6),(35,4,8,6),(36,4,9,6),(37,5,1,4),(38,5,2,4),(39,5,3,4),(40,5,4,5),(41,5,5,5),(42,5,6,5),(43,5,7,6),(44,5,8,6),(45,5,9,6),(46,6,1,4),(47,6,2,4),(48,6,3,4),(49,6,4,5),(50,6,5,5),(51,6,6,5),(52,6,7,6),(53,6,8,6),(54,6,9,6),(55,7,1,7),(56,7,2,7),(57,7,3,7),(58,7,4,8),(59,7,5,8),(60,7,6,8),(61,7,7,9),(62,7,8,9),(63,7,9,9),(64,8,1,7),(65,8,2,7),(66,8,3,7),(67,8,4,8),(68,8,5,8),(69,8,6,8),(70,8,7,9),(71,8,8,9),(72,8,9,9),(73,9,1,7),(74,9,2,7),(75,9,3,7),(76,9,4,8),(77,9,5,8),(78,9,6,8),(79,9,7,9),(80,9,8,9),(81,9,9,9)
/*
------------------------------------------------------------------------------------------------------------------------------------
STORE PUZZLE
------------------------------------------------------------------------------------------------------------------------------------
*/
/* add fixed puzzle cells -- 0 for empty cells - row of first 9 values and so forth */
insert into #tFixed (CoordinateID, Value)
select CoordinateID, substring(@PuzzleIn,CoordinateID,1) Value
from #tGrid
where substring(@PuzzleIn,CoordinateID,1) != 0
insert into #tOption (CoordinateID, Value)
select CoordinateID, Num from #tGrid a cross join
(select top 9 ROW_NUMBER() over (order by CoordinateID) Num from #tGrid) b
/* exclude fixed coordinates*/
where not exists
(select 1 from #tFixed c where a.CoordinateID = c.CoordinateID)
/* exclude row */
and not exists
(select 1 from #tFixed c inner join #tGrid d on c.CoordinateID = d.CoordinateID where a.RowNum = d.RowNum and b.Num = c.Value)
/* exclude column */
and not exists
(select 1 from #tFixed c inner join #tGrid d on c.CoordinateID = d.CoordinateID where a.ColumnNum = d.ColumnNum and b.Num = c.Value)
/* exclude value same BlockNum */
and not exists
(select 1 from #tFixed c inner join #tGrid d on c.CoordinateID = d.CoordinateID where a.BlockNum = d.BlockNum and b.Num = c.Value)
/* add back fixed values */
union
select CoordinateID, Value from #tFixed
--------------------
/* SOLVE */
--------------------
set @Select = ''
set @Exclusion = ''
set @sql = ''
set @Select = ''
set @Exclusion = ''
set @sql = ''
/*produces 81 values in row preference order a row is one permutation of possible values*/
SELECT @Select = stuff(
(select 'cross join'+'(select Value ['+CoordinateID+'] from #tOption where CoordinateID = '+CoordinateID+') ['+CoordinateID+']' from
(select distinct cast(CoordinateID as varchar(3)) CoordinateID from #tOption) b
order by cast(CoordinateID as int) FOR XML PATH('')), 1, 10, '')
/* row, column or block exclusions - all one way permutations with the CoordinateID > other */
select @Exclusion = @Exclusion + ' and ['+cast(l.CoordinateID as varchar(5))+'] <> ['+cast(r.CoordinateID as varchar(5))+']'
from #tGrid l cross join #tGrid r
where (l.RowNum = r.RowNum or l.ColumnNum = r.ColumnNum or l.BlockNum = r.BlockNum) and r.CoordinateID > l.CoordinateID
/* run whole thing - insert into #solution*/
/* solve */
set @sql = 'select ROW_NUMBER() over (order by [1] asc) SolutionID, *
from (select * from '+@Select+' where 1 = 1 '+@Exclusion+') x '
insert into #solutions
exec (@SQL)
/* store solution in @PuzzleSolution */
select top 1 @PuzzleSolution = [1]+[2]+[3]+[4]+[5]+[6]+[7]+[8]+[9]+[10]+[11]+[12]+[13]+[14]+[15]+[16]+[17]+[18]+[19]+[20]+[21]+[22]+[23]+[24]+[25]+[26]+[27]+[28]+[29]+[30]+[31]+[32]+[33]+[34]+[35]+[36]+[37]+[38]+[39]+[40]+[41]+[42]+[43]+[44]+[45]+[46]+[47]+[48]+[49]+[50]+[51]+[52]+[53]+[54]+[55]+[56]+[57]+[58]+[59]+[60]+[61]+[62]+[63]+[64]+[65]+[66]+[67]+[68]+[69]+[70]+[71]+[72]+[73]+[74]+[75]+[76]+[77]+[78]+[79]+[80]+[81] from #solutions
/* show puzzle */
select RowNum, [1],[2],[3],[4],[5],[6],[7],[8],[9]
from
(select RowNum, ColumnNum, case when substring(@PuzzleIn,CoordinateID,1) != 0 then substring(@PuzzleIn,CoordinateID,1) end Value from #tGrid) as base
pivot
(min(Value) for ColumnNum in ([1],[2],[3],[4],[5],[6],[7],[8],[9])) as pt
/* Show options */
select RowNum, [1],[2],[3],[4],[5],[6],[7],[8],[9]
from
(select distinct RowNum, ColumnNum,
(SELECT stuff(
(select ','+cast(Value as char(1)) from
#tOption b where a.CoordinateID = b.CoordinateID
FOR XML PATH('')), 1, 1, '')) Value
from #tGrid a) as base
pivot (min(Value) for ColumnNum in ([1],[2],[3],[4],[5],[6],[7],[8],[9])) as pt
/* show solution */
select RowNum, [1],[2],[3],[4],[5],[6],[7],[8],[9]
from
(select RowNum, ColumnNum, case when substring(@PuzzleSolution,CoordinateID,1) != 0 then substring(@PuzzleSolution,CoordinateID,1) end Value from #tGrid) as base
pivot (min(Value) for ColumnNum in ([1],[2],[3],[4],[5],[6],[7],[8],[9])) as pt
go
February 20, 2018 at 5:08 am
February 20, 2018 at 6:06 am
This code is interesting but seems to be completly bugged :/
I ran the first sample : exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
the exposed solution is completly false, and almost alls initals values have been lost.
# 1 2 3 4 5 6 7 8 9
1 5 8 9 4 6 2 1 7 5 (0x3, 2x5, all initials lost)
2 3 1 2 6 7 3 5 4 2 (2x2, 2x3, 0x8, 0x9, initial 2 lost)
3 8 9 6 7 3 1 8 9 2 (0x4, 0x5, 2x8, 2x9, all initials lost)
4 5 3 4 2 8 5 7 1 4 (2x4, 2x5, 0x6, 0x9, initials 1,5,3 lost)
5 3 6 9 7 4 3 9 5 8 (0x1, 0x2, 2x3, 2x9, all initials lost)
6 6 7 1 2 8 3 1 8 2 (2x1, 2x2, 0x4, 0x5, 2x8, 0x9, initials 439 lost)
7 7 9 5 9 4 6 7 4 2 (0x1, 0x3, 2x4, 2x7, 0x8, 2x9, all initials lost)
8 9 3 6 4 8 1 5 9 5 (0x2, 2x5, 0x7, 2x9, all initials lost)
9 6 4 1 8 3 6 7 2 1 (2x1, 0x5, 2x6, 2x9, all initials lost)
and so on for the columns.
I'll take a deeper look inside tonight.
Did i have miss something from your code or the article ?
February 20, 2018 at 6:47 am
Same thing here. I used the code attached to the article, and the result set has almost all initial values replaced with other values and the results is not valid either.
February 20, 2018 at 7:01 am
Dude76 - Tuesday, February 20, 2018 6:06 AMThis code is interesting but seems to be completly bugged :/
I ran the first sample : exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
the exposed solution is completly false, and almost alls initals values have been lost.
# 1 2 3 4 5 6 7 8 9
1 5 8 9 4 6 2 1 7 5 (0x3, 2x5, all initials lost)
2 3 1 2 6 7 3 5 4 2 (2x2, 2x3, 0x8, 0x9, initial 2 lost)
3 8 9 6 7 3 1 8 9 2 (0x4, 0x5, 2x8, 2x9, all initials lost)
4 5 3 4 2 8 5 7 1 4 (2x4, 2x5, 0x6, 0x9, initials 1,5,3 lost)
5 3 6 9 7 4 3 9 5 8 (0x1, 0x2, 2x3, 2x9, all initials lost)
6 6 7 1 2 8 3 1 8 2 (2x1, 2x2, 0x4, 0x5, 2x8, 0x9, initials 439 lost)
7 7 9 5 9 4 6 7 4 2 (0x1, 0x3, 2x4, 2x7, 0x8, 2x9, all initials lost)
8 9 3 6 4 8 1 5 9 5 (0x2, 2x5, 0x7, 2x9, all initials lost)
9 6 4 1 8 3 6 7 2 1 (2x1, 0x5, 2x6, 2x9, all initials lost)and so on for the columns.
I'll take a deeper look inside tonight.Did i have miss something from your code or the article ?
Dude76 - Tuesday, February 20, 2018 6:06 AMThis code is interesting but seems to be completly bugged :/
I ran the first sample : exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
the exposed solution is completly false, and almost alls initals values have been lost.
# 1 2 3 4 5 6 7 8 9
1 5 8 9 4 6 2 1 7 5 (0x3, 2x5, all initials lost)
2 3 1 2 6 7 3 5 4 2 (2x2, 2x3, 0x8, 0x9, initial 2 lost)
3 8 9 6 7 3 1 8 9 2 (0x4, 0x5, 2x8, 2x9, all initials lost)
4 5 3 4 2 8 5 7 1 4 (2x4, 2x5, 0x6, 0x9, initials 1,5,3 lost)
5 3 6 9 7 4 3 9 5 8 (0x1, 0x2, 2x3, 2x9, all initials lost)
6 6 7 1 2 8 3 1 8 2 (2x1, 2x2, 0x4, 0x5, 2x8, 0x9, initials 439 lost)
7 7 9 5 9 4 6 7 4 2 (0x1, 0x3, 2x4, 2x7, 0x8, 2x9, all initials lost)
8 9 3 6 4 8 1 5 9 5 (0x2, 2x5, 0x7, 2x9, all initials lost)
9 6 4 1 8 3 6 7 2 1 (2x1, 0x5, 2x6, 2x9, all initials lost)and so on for the columns.
I'll take a deeper look inside tonight.Did i have miss something from your code or the article ?
Hi Dude76
YES - there is an order by missing from the code that generates the select part of the statement. It should read
/*produces 81 values in row preference order a row is one permutation of possible values*/
SELECT @Select = stuff(
(select 'cross join'+'(select Value ['+CoordinateID+'] from #tOption where CoordinateID = '+CoordinateID+') ['+CoordinateID+']' from
(select distinct cast(CoordinateID as varchar(3)) CoordinateID from #tOption) b
order by cast(CoordinateID as int) FOR XML PATH('')), 1, 10, '')
The current code displays as 1, 10, 11, etc so results are complete garbage!
Thanks for finding this - was a last minute change - clearly untested!!!
Thanks
Bevan
February 20, 2018 at 7:02 am
Richard M. - Tuesday, February 20, 2018 6:47 AMSame thing here. I used the code attached to the article, and the result set has almost all initial values replaced with other values and the results is not valid either.
YES - there is an order by missing from the code that generates the select part of the statement. It should read
/*produces 81 values in row preference order a row is one permutation of possible values*/
SELECT @Select = stuff(
(select 'cross join'+'(select Value ['+CoordinateID+'] from #tOption where CoordinateID = '+CoordinateID+') ['+CoordinateID+']' from
(select distinct cast(CoordinateID as varchar(3)) CoordinateID from #tOption) b
order by cast(CoordinateID as int) FOR XML PATH('')), 1, 10, '')
The current code displays as 1, 10, 11, etc so results are complete garbage!
Thanks for finding this - was a last minute change - clearly untested!!!
Thanks
Bevan
February 20, 2018 at 7:59 am
Dude76 - Tuesday, February 20, 2018 6:06 AMThis code is interesting but seems to be completly bugged :/
I ran the first sample : exec sp_sudoku_solve_simple '023780460000620000060304080001000534280000097439000100010205040000036000056018370'
the exposed solution is completly false, and almost alls initals values have been lost.
# 1 2 3 4 5 6 7 8 9
1 5 8 9 4 6 2 1 7 5 (0x3, 2x5, all initials lost)
2 3 1 2 6 7 3 5 4 2 (2x2, 2x3, 0x8, 0x9, initial 2 lost)
3 8 9 6 7 3 1 8 9 2 (0x4, 0x5, 2x8, 2x9, all initials lost)
4 5 3 4 2 8 5 7 1 4 (2x4, 2x5, 0x6, 0x9, initials 1,5,3 lost)
5 3 6 9 7 4 3 9 5 8 (0x1, 0x2, 2x3, 2x9, all initials lost)
6 6 7 1 2 8 3 1 8 2 (2x1, 2x2, 0x4, 0x5, 2x8, 0x9, initials 439 lost)
7 7 9 5 9 4 6 7 4 2 (0x1, 0x3, 2x4, 2x7, 0x8, 2x9, all initials lost)
8 9 3 6 4 8 1 5 9 5 (0x2, 2x5, 0x7, 2x9, all initials lost)
9 6 4 1 8 3 6 7 2 1 (2x1, 0x5, 2x6, 2x9, all initials lost)and so on for the columns.
I'll take a deeper look inside tonight.Did i have miss something from your code or the article ?
I have fixed it and the it has been added to the site. Thanks for this!!
Was a missing order by so the fields were coming through in the order 1, 10, 11, 12, etc and stored into a table ordered in sequence!!
Thanks
Bevan
February 20, 2018 at 8:39 am
There was a great article how to solve Sudoku by Itzik Ben Gun about 12 years ago in SQL Server Magazine.
February 20, 2018 at 8:56 am
February 20, 2018 at 6:41 pm
Richard M. - Tuesday, February 20, 2018 8:56 AMThanks Bevan! Seems that order clause fixed the issue. Look like the output is now correct.
Thanks Richard - another lesson in not testing properly!
February 20, 2018 at 6:45 pm
SQL Guy 1 - Tuesday, February 20, 2018 8:39 AMThere was a great article how to solve Sudoku by Itzik Ben Gun about 12 years ago in SQL Server Magazine.
I'll have to have a look around at how others have solved this - for this exercise it was attempting without looking at solutions however I am keen to see how others have approached it now.
Thanks for your comment
Bevan
February 20, 2018 at 11:36 pm
Seems it works now.
I would like to understand the query
select RowNum, [1],[2],[3],[4],[5],[6],[7],[8],[9]
from
(select RowNum, ColumnNum, case when substring(@PuzzleIn,CoordinateID,1) != 0 then substring(@PuzzleIn,CoordinateID,1) end Value from #tGrid) as base
pivot
(min(Value) for ColumnNum in ([1],[2],[3],[4],[5],[6],[7],[8],[9])) as pt
what is the meaning of !=0
Thanks
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