SuDoKu challenge

[eibwenbv]

I am totally new to Visual Basic and started out with a copy of version 4 that I was given. I am hooked. I enjoy writing code and am looking forward to creating my own spins on different code projects just like the rest of you.

I have put together a small program for the totally beat-to-death term SuDoKu and am having trouble with generating the boards (arrays) to display.

I have did this thus far:

[Dim MyNum(9,9) As Integer]

[ for x = 1 to 9 ]

[ for y = 1 ro 9 ]


[newZ:]
[Randomize]
[z = Int( ( 9 * RND) + 1)]

[if y = 1 then goto getnewnum]
[ for w = ( y - 1) to 1 Step -1]
[ if MyNum(x , y) = MyNum(x , w) then goto newZ]
[ next w]

[if x = 1 then goto getnewnum]
[ for v = (x - 1) to 1 Step -1]
[ if MyNum(x , y) = MyNum(v , y) then goto newZ]
[ next v]

[getnewnum]
[next y, x]


I have done the "homework" suggested by the web page authors. There are many posts that I see that are written for you more experienced programmers, but none for me. Does anyone have a clue how to assist me or even want to try?
I would appreciate some assistance.

[kadghar]

This might be of help:

Random Filled Array

[eibwenbv]

I have alreaady viewed that post and it seemed way to confusing. I did not wish to convert any of the numbers in the arrays to just "1's" and "2's".

Additionally, trying the code before I made my original post left me with duplicates in my 3 x 3 arrays and in my vertical arrays (columns).

No one seems to go past the first row. Do only SuDoKu book makers have the ability to do this? I would guess that VB4 is powerful enough to handle this task,
but fully willing to admit that I could be wrong because I am new.

Confused!!!!!!! !!!!

[kadghar]

I have alreaady viewed that post and it seemed way to confusing. I did not wish to convert any of the numbers in the arrays to just "1's" and "2's".

Additionally, trying the code before I made my original post left me with duplicates in my 3 x 3 arrays and in my vertical arrays (columns).

No one seems to go past the first row. Do only SuDoKu book makers have the ability to do this? I would guess that VB4 is powerful enough to handle this task,
but fully willing to admit that I could be wrong because I am new.

Confused!!!!!!! !!!!

Check out the las option, in this case, for the sudoku, only consider the 3x3 squares, start generating the 1st, 4th and 7th row:

123456789
234567891
345678912

then the 2nd, 5th and 8th, and finaly the 3rd, 6th and 9th, will be something like:

123456789
456789123
879123456
234567891
567891234
891235467
345678912
678912345
912345678

Then just randomly change columns and rows, but be sure that you'll only change column
1 with 2 or 3,
4 with 5 or 6,
7 with 8 or 9 and the same for rows..
you can also change sets of 3 columns and sets of 3 rows
do this a random number of times and you'll have a nice sudoku board

[kadghar]

oh, and i forgot to tell you
if you want it even more randomly, remember that 123456789 is not the only original sequence, you can create an alternative one at random, lets say:

159362874

and follow the same procedure, so you'll get:

159 362 874
362 874 159
874 159 362

593 628 741
628 741 593
741 593 628

936 287 415
287 415 936
415 936 287

And then swap columns and rows.

[eibwenbv]

Please forgive me for taking so long to reply.

I also do not want to sound like an idiot, lazy or selfish, but exactly how do you do the things that you have described in code?

Please remember two things:

1) I am running an older version of VB (version 4, heck I got it for free!)
2) I am new to coding

I do realize that all of your time is valuable to you, so can you sorta "block" out the steps for me? I have already tried several approaches on my machine but they all take too long to come back with a properly filled in board quickly (yes my machine is fast enough).

Thank you fourm for your kindness, understanding and help.

eibwenbv

[kadghar]

...
1) I am running an older version of VB (version 4, heck I got it for free!)
2) I am new to coding

VB 4?!! yeah!! i loved that version, it was the first one i had.

And i apologize if im being confusing.

What im saying is that if you try to randomly generate an array with 1 to 9 x 1 to 9 numbers, it will be harder to make it a sudoku board. So what you should do is to generate a "basic board" and then swap some rows and columns, but swap them in a way that it'll keep the "sudoku's properties".

a basic sudoku board will be something like this

 F G            HI
123    456    789
456    789    123
789    123    456

234    567    891
567    891    234       A
891    234    567       B

345    678    912
678    912    345       D
912    345    678       E

And you can swap any column or any row in the same "block of three"
i.e. you can swap the whole row A with the B or D with E, but you cannot swap A with E.
Same, you can swap columns F and G but not F with H

And as you can see, you can replace every 1 with 3 and every 3 with 1 in the matrix... or every 9 with a 6, every 6 with a 4 and every 4 with a 9... it doesnt matter which number you have as long as they follow an order, so it will be nice that istead of creating this "original sudoku board" based in 123456789 sequence, use it as the "index map"

So, generate a 9x1 array with numbers 1 to 9 and use the "index map" e.g.

Generate a random array that could look like this

Arr1 = {4,7,5,6,8,2,1, 9,3}

And the "basic board" will be (supose the indexes go from 1 to 9 instead of 0 to 8) i.e.

arr1(1)arr1(2)arr1(3)      arr1(4)arr1(5)arr1(6)     arr1(7)arr1(8)arr1(9)
arr1(4)arr1(5)arr1(6)      arr1(7)arr1(8)arr1(9)     arr1(1)arr1(2)arr1(3)
arr1(7)arr1(8)arr1(9)      arr1(1)arr1(2)arr1(3)     arr1(4)arr1(5)arr1(6)
(..)

And so on, so it'll look like:

745    682    193
682    193    745
193    745    682

456    821    937
821    937    456
937    456    821

568    219    374
219    374    568
374    568    219

And then make the swaps on this array.

That should be the main idea.

with a coulpe of arrays and some FOR or DO you should be able to do it, give it a try and if you have any further question just post it here.

HTH

[Tig201]

where is that pesky subscribing button.
BTW Nifty Trick kadghar.

[eibwenbv]

Wow, I am so sorry I asked. I am so still confused
I thought my arrays (in the code above) allowed me to put these numbers
in any order I wanted, in any group of three I wanted, row, column or box
I wanted. Am I wrong?


When these sudoku book publishers create puzzles, how do they do it?
I appreciate all you guys, if no more posts appear here, have the admin
remove my access.


thanks for your time

[kadghar]

Wow, I am so sorry I asked. I am so still confused
I thought my arrays (in the code above) allowed me to put these numbers
in any order I wanted, in any group of three I wanted, row, column or box
I wanted. Am I wrong?

I tried to run your code but it didnt asigned the Z to the array, so i assumed (sorry if i mistaked) that what you wanted to do is something like this:

[CODE=vb]Dim MyNum(9, 9) As Integer
For x = 1 To 9
For y = 1 To 9
newZ:
Randomize
z = Int((9 * Rnd) + 1)
If y = 1 Then GoTo getnewnum
For w = (y - 1) To 1 Step -1
If z = MyNum(x, w) Then GoTo newZ
Next w
If x = 1 Then GoTo getnewnum
For v = (x - 1) To 1 Step -1
If z = MyNum(v, y) Then GoTo newZ
MyNum(x, y) = z
Next v
getnewnum:
Next y, x[/CODE]

Even then, the array will not be finished in most of the cases, this is because the probability of having a "free space" is decreasing.

lets say you have the 5x5 board and you are asigning the number 5 and your array is something like:

1 3 4 5 2
4 2 5 1 3
3 1 2 4 5
2 4 1 3 X

The only free space for that number is X but you cannot put there a 5 or any other number, then your code will enter into an infinite loop. That's why i recomended you to generate a table with one of the permutations of the problem and make columns and rows swaping. of course this method has many many limitations but will give you a solution after all.

[eibwenbv]

Like I said, I am so sorry, I give up.

I just don't get it.

I know why it don't work

ADMIN: please remove my access from the forum

Thanks guys!

later