Fast sudoku solver

Monkey Forums/Monkey Programming/Fast sudoku solver

mbsoft

(Posted 2014) [#1]

strict

global start:Int[]=
[ 0,308,0,
75,0,180,
2,10,400,
510,30,96,
0,0,0,
640,90,18,
8,60,900,
91,0,670,
0,905,0 ]

Global indexes:Int[]=
[ 0,9,18,0,10,18,0,11,18,
0,12,19,0,13,19,0,14,19,
0,15,20,0,16,20,0,17,20,
1,9,18,1,10,18,1,11,18,
1,12,19,1,13,19,1,14,19,
1,15,20,1,16,20,1,17,20,
2,9,18,2,10,18,2,11,18,
2,12,19,2,13,19,2,14,19,
2,15,20,2,16,20,2,17,20,
3,9,21,3,10,21,3,11,21,
3,12,22,3,13,22,3,14,22,
3,15,23,3,16,23,3,17,23,
4,9,21,4,10,21,4,11,21,
4,12,22,4,13,22,4,14,22,
4,15,23,4,16,23,4,17,23,
5,9,21,5,10,21,5,11,21,
5,12,22,5,13,22,5,14,22,
5,15,23,5,16,23,5,17,23,
6,9,24,6,10,24,6,11,24,
6,12,25,6,13,25,6,14,25,
6,15,26,6,16,26,6,17,26,
7,9,24,7,10,24,7,11,24,
7,12,25,7,13,25,7,14,25,
7,15,26,7,16,26,7,17,26,
8,9,24,8,10,24,8,11,24,
8,12,25,8,13,25,8,14,25,
8,15,26,8,16,26,8,17,26 ]

Global Number_of_bits:Int[]=[
0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,5,6,6,7,6,7,7,8,6,7,7,8,7,8,8,9]

Global Highest_bitnumber:Int[]=[ ' Return highest bitnumber + 1
0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9]

Class Myerr Extends Throwable
Field msg:string
Method New(s:String)
msg=s
End method
End class

Class sudoku
Const RASTERSIZE:=81
Const FREESIZE:=27
Field raster:Int[RASTERSIZE]
Field free:Int[FREESIZE]
Field stack:Int[RASTERSIZE]
Field sp:int
Field i0:Int,i1:Int,i2:Int
Field freebits:Int
Field solutioncnt:int

Method reset_all_free:Void()
For Local i:Int=0 Until FREESIZE free[i]=$1ff Next
End

Method init_stack:Void()
sp=0
For Local i:Int=0 Until RASTERSIZE
If raster[i]=0
stack[sp]=i
sp+=1
end
end
End

Method init:Void(startraster:Int[])
If startraster.Length<>FREESIZE Throw New Myerr("Startraster length not 27 !!")
Local t:Int,z:Int,i:Int,x:Int
solutioncnt=0
sp=0
reset_all_free
For i=0 Until RASTERSIZE raster[i]=0 next
x=RASTERSIZE-1
For i=FREESIZE-1 To 0 Step -1
z=startraster[i]
For Local j:Int=1 To 3
t=z Mod 10
If t<>0 set_occupied x,(1 Shl (t-1))
z/=10
x-=1
next
Next
init_stack
end

Method New(is:Int[])
init is
End Method

Method showraster:Void()
Local n:Int=0,v:Int=0,n2:Int=0,n3:Int=0
Local s:String=""
For Local i:Int=0 Until RASTERSIZE
v=v*10+Highest_bitnumber[raster[i]]
n+=1
If n=3
If s="" s+=v Else s+=("|"+v)
n=0
v=0
n2+=1
Endif
If n2=3 Print(s) s="" n2=0 n3+=1
If n3=3 And i<>(RASTERSIZE-1)
n3=0
Print("---+---+---")
end
next
End Method

Method set_indexes:Void(pos:Int)
pos=(pos Shl 1) + pos 'pos*=3
i0=indexes[pos+0]
i1=indexes[pos+1]
i2=indexes[pos+2]
End

Method get_free:void(pos:Int)
set_indexes pos
freebits=free[i0] & free[i1] & free[i2]
End

Method set_free:Void(pos:Int) ' n goes from 1 to 9
Local n:Int=raster[pos]
If n=0 return
raster[pos]=0
set_indexes pos
free[i0]|=n free[i1]|=n free[i2]|=n
End

Method set_occupied:Void(pos:Int,n:Int)
set_indexes pos
raster[pos]=n
free[i0]~=n free[i1]~=n free[i2]~=n
End

Method find_best_pos:Int()
Local n:Int,oldn:Int=9,newpos:Int=RASTERSIZE,pos:Int,i:Int,x:Int=-1
Local fb:Int=0
i=sp-1
While i>=0
pos=stack[i]
get_free(pos)
n=Number_of_bits[freebits]
If n=0 Return -1
If n=1
newpos=pos
x=i
Exit
end
If n<oldn
oldn=n
newpos=pos
fb=freebits
x=i
End
i-=1
End
sp-=1
stack[x]=stack[sp]
If n>1 freebits=fb
Return newpos
End

Method solveloop:Void()
If sp=0
If solutioncnt=0
showraster
solutioncnt+=1
Else
Throw New Myerr("Aborted. More then 1 solution !!")
end
Return
end

Local pos:Int,bm:Int,t:Int
pos=find_best_pos()
If pos<0 Return
bm=freebits
While bm
t=1 Shl (Highest_bitnumber[bm]-1)
set_occupied pos,t
solveloop
set_free pos
bm~=t
Wend
stack[sp]=pos
sp+=1
end

Method solve:Void()
init start
Print ""
solveloop
If solutioncnt=0 Throw New Myerr("No solution found !!")
End

End Class

Function Main:Int()
Try

Local s:sudoku= New sudoku(start)
s.solve

Catch ex:Myerr
Print ex.msg
End
Return 0
End function

Fred	(Posted 2014) [#2]

well done !

ziggy

(Posted 2014) [#3]

Here an indented version (just cut & pasted into Jungle Ide) and added a couple of missing ;

Strict

Global start:Int[] =
	[0, 308, 0,
	75, 0, 180,
	2, 10, 400,
	510, 30, 96,
	0, 0, 0,
	640, 90, 18,
	8,60,900 ,
	91, 0, 670,
	0, 905, 0]

Global indexes:Int[] =
	[0, 9, 18, 0, 10, 18, 0, 11, 18,
	0, 12, 19, 0, 13, 19, 0, 14, 19,
	0, 15, 20, 0, 16, 20, 0, 17, 20,
	1, 9, 18, 1, 10, 18, 1, 11, 18,
	1, 12, 19, 1, 13, 19, 1, 14, 19,
	1, 15, 20, 1, 16, 20, 1, 17, 20,
	2, 9, 18, 2, 10, 18, 2, 11, 18,
	2, 12, 19, 2, 13, 19, 2, 14, 19,
	2, 15, 20, 2, 16, 20, 2, 17, 20,
	3, 9, 21, 3, 10, 21, 3, 11, 21,
	3, 12, 22, 3, 13, 22, 3, 14, 22,
	3, 15, 23, 3, 16, 23, 3, 17, 23,
	4, 9, 21, 4, 10, 21, 4, 11, 21,
	4, 12, 22, 4, 13, 22, 4, 14, 22,
	4, 15, 23, 4, 16, 23, 4, 17, 23,
	5, 9, 21, 5, 10, 21, 5, 11, 21,
	5, 12, 22, 5, 13, 22, 5, 14, 22,
	5, 15, 23, 5, 16, 23, 5, 17, 23,
	6, 9, 24, 6, 10, 24, 6, 11, 24,
	6, 12, 25, 6, 13, 25, 6, 14, 25,
	6, 15, 26, 6, 16, 26, 6, 17, 26,
	7, 9, 24, 7, 10, 24, 7, 11, 24,
	7, 12, 25, 7, 13, 25, 7, 14, 25,
	7, 15, 26, 7, 16, 26, 7, 17, 26,
	8, 9, 24, 8, 10, 24, 8, 11, 24,
	8, 12, 25, 8, 13, 25, 8, 14, 25,
	8, 15, 26, 8, 16, 26, 8, 17, 26]


Global Number_of_bits:Int[]=[
	0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
	1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
	1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
	1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
	3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
	3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
	4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8, 5, 6, 6, 7, 6, 7, 7, 8, 6, 7, 7, 8, 7, 8, 8, 9]
 
Global Highest_bitnumber:Int[]=[ ' Return highest bitnumber + 1
	0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9]
 

 Class Myerr Extends Throwable
	Field msg:string
	Method New(s:String)
		msg = s
	End Method
End Class

Class sudoku
	Const RASTERSIZE:= 81
	Const FREESIZE:= 27
	Field raster:Int[RASTERSIZE]
	Field free:Int[FREESIZE]
	Field stack:Int[RASTERSIZE]
	Field sp:int
	Field i0:Int, i1:Int, i2:Int
	Field freebits:Int
	Field solutioncnt:int

	Method reset_all_free:Void()
		For Local i:Int = 0 Until FREESIZE; free[i] = $1ff; Next
	End

	Method init_stack:Void()
		sp = 0
		For Local i:Int = 0 Until RASTERSIZE
			If raster[i] = 0
				stack[sp] = i
				sp += 1
			end
		end
	End

	Method init:Void(startraster:Int[])
		If startraster.Length <> FREESIZE Throw New Myerr("Startraster length not 27 !!")
		Local t:Int, z:Int, i:Int, x:Int
		solutioncnt = 0
		sp = 0
		reset_all_free
		For i = 0 Until RASTERSIZE raster[i] = 0; Next
		x = RASTERSIZE - 1
		For i = FREESIZE - 1 To 0 Step - 1
			z = startraster[i]
			For Local j:Int=1 To 3
				t = z Mod 10
				If t <> 0 set_occupied x, (1 Shl (t - 1))
				z /= 10
				x -= 1
			next
		Next
		init_stack
	End

	Method New(is:Int[])
		init is
	End Method

	Method showraster:Void()
		Local n:Int = 0, v:Int = 0, n2:Int = 0, n3:Int = 0
		Local s:String = ""
		For Local i:Int = 0 Until RASTERSIZE
			v = v * 10 + Highest_bitnumber[raster[i]]
			n += 1
			If n = 3
				If s = "" s += v Else s += ("|" + v)
				n = 0
				v = 0
				n2 += 1
			EndIf
			If n2 = 3 Print(s) s = "" n2 = 0 n3 += 1
			If n3 = 3 And i <> (RASTERSIZE - 1)
				n3 = 0
				Print("---+---+---")
			End
		Next
	End Method

	Method set_indexes:Void(pos:Int)
		pos = (pos Shl 1) + pos 'pos*=3
		i0 = indexes[pos + 0]
		i1 = indexes[pos + 1]
		i2 = indexes[pos + 2]
	End

	Method get_free:Void(pos:Int)
		set_indexes pos
		freebits = free[i0] & free[i1] & free[i2]
	End

	Method set_free:Void(pos:Int) ' n goes from 1 to 9
		Local n:Int = raster[pos]
		If n = 0 Return
		raster[pos] = 0
		set_indexes pos
		free[i0] |= n free[i1] |= n free[i2] |= n
	End

	Method set_occupied:Void(pos:Int, n:Int)
		set_indexes pos
		raster[pos]=n 
		free[i0] ~= n free[i1] ~= n free[i2] ~= n
	End


	Method find_best_pos:Int()
		Local n:Int, oldn:Int = 9, newpos:Int = RASTERSIZE, pos:Int, i:Int, x:Int = -1
		Local fb:Int = 0
		i = sp - 1
		While i >= 0
			pos = stack[i]
			get_free(pos)
			n = Number_of_bits[freebits]
			If n = 0 Return - 1
			If n = 1
				newpos = pos
				x = i
				Exit
			End
			If n < oldn
				oldn = n
				newpos = pos
				fb = freebits
				x = i
			End
			i -= 1
		End
		sp -= 1
		stack[x] = stack[sp]
		If n > 1 freebits = fb
		Return newpos
	End


	Method solveloop:Void()
		If sp = 0
			If solutioncnt = 0
				showraster
				solutioncnt += 1
			Else
				Throw New Myerr("Aborted. More then 1 solution !!")
			end
			Return
		end

		Local pos:Int, bm:Int, t:Int
		pos = find_best_pos()
		If pos < 0 Return
		bm = freebits
		While bm
			t = 1 Shl (Highest_bitnumber[bm] - 1)
			set_occupied pos, t
			solveloop
			set_free pos
			bm ~= t
		Wend
		stack[sp] = pos
		sp += 1
	end

	Method solve:Void()
		init start
		Print ""
		solveloop
		If solutioncnt = 0 Throw New Myerr("No solution found !!")
	End

End Class

Function Main:Int()
	Try

		Local s:sudoku = New sudoku(start)
		s.solve

	Catch ex:Myerr
		Print ex.msg
	End
	Return 0
End Function