# Sodoku-Generator

Hi,

with Google I found a Quiz about a Sodoku-solver, but I didn’t find a
Sodoku generator. Also RAA and RubyForge did not list one.

Is there any out there ? May be one, which also generated a solution
for the generated Sodokus?

Kind regards,
mcc

From the R library package “sudoku”:

generateSudoku package:sudoku R Documentation

Randomly Generate a Sudoku Puzzle Grid

Description:

`````` Creates a 9x9 Sudoku grid suitable for use by 'playSudoku'.
``````

Usage:

``````   generateSudoku(Nblank=50, print.it=FALSE)
``````

Arguments:

Nblank: Number of cells to blank out

print.it: Logical. If true, print result to screen.

Details:

`````` The basic algorithm is to start with a 'primordial' Sudoku grid,
swap around some rows and columns, then blank out some cells.
``````

Value:

`````` A matrix, representing a 9x9 Sudoku grid.
``````

Author(s):

`````` Curt S. <[email protected]>, Henrik Bengtsson
<[email protected]>, and David Brahm <[email protected]>
``````

References:

`````` <URL: http://sudoku.com/>
``````

Examples:

`````` generateSudoku(print.it=TRUE)
``````

Here’s the function definition for those who understand R. I might make
pseudo-code from this if I have the time:

generateSudoku ← function(Nblank=50, print.it=FALSE) {
z ←
c(1:9,4:9,1:3,7:9,1:6,2:9,1,5:9,1:4,8:9,1:7,3:9,1:2,6:9,1:5,9,1:8)
z ← matrix(sample(9)[z], 9,9)
for (i in 1:5) z ← z[replicate(3, sample(3)) + 3rep(sample(0:2),
each=3),
replicate(3, sample(3)) + 3
rep(sample(0:2),
each=3)]
for (bi in seq(0,6,3)) for (bj in seq(0,6,3)) {
idx ← data.matrix(expand.grid(bi + 1:3, bj + 1:3))
z[idx[sample(1:9, Nblank%/%9), ]] ← 0
}

## Depopulate (if we had a test for uniqueness, we’d put it here):

while (sum(!z) < Nblank) z[matrix(sample(9,2), 1)] ← 0
if (print.it) printSudoku(z)
z
}

Meino Christian C. wrote:

From: “M. Edward (Ed) Borasky” [email protected]
Subject: Re: Sodoku-Generator
Date: Mon, 20 Feb 2006 04:48:30 +0900

Hi Edward,

I found nothing at RAA/Rubyforge due to a typo I did:
S_u_doku is correct…I searched for “S_o_doku”…

Sorry for the trouble…

(rsudoku did not start, because it doesn’t find a certain preference
file
in my \$HOME. INSTALL says: Simpy start ruby rsudoku.rb.

I will check this…

Ruby!
mcc

Hi!

At Mon, 20 Feb 2006 04:08:01 +0900, Meino Christian C. wrote:

with Google I found a Quiz about a Sodoku-solver, but I didn’t find
a Sodoku generator. Also RAA and RubyForge did not list one.

Is there any out there ? May be one, which also generated a solution
for the generated Sodokus?

http://www.puzzle.jp

I understand that you rather seek for a program but … hand-made
Sudoku are much more fun than those created by software. Up to now at
least.

Josef ‘Jupp’ Schugt

On Feb 19, 2006, at 2:18 PM, Josef ‘Jupp’ SCHUGT wrote:

I understand that you rather seek for a program but … hand-made
Sudoku are much more fun than those created by software. Up to now at
least.

This is slightly OT, so I’ll only offer this one contribution…
There is no such thing as hand-made sudoku puzzles at this point.
Yes, some newspapers still make the claim, but it’s simply untrue.

–Steve

Stephen W. wrote:

newspapers still make the claim, but it’s simply untrue.
I think I’m the last person in the world to “get” this phenomenon.
I’ve never tried it, but it looks as exciting as solving the same
crossword puzzle over and over.

I guess it’s the Rubik’s Cube of the 00’s, for whatever that may
be worth.

Hal

From: Josef ‘Jupp’ SCHUGT [email protected]
Subject: Re: Sodoku-Generator
Date: Mon, 20 Feb 2006 07:18:20 +0900

Hi Josef,

One could see the implementation of a sudoku-generator in ruby as a
meta-puzzle: The puzzle to implement a puzzle-generator :))

Have a nice day!
mcc

Stephen W. [email protected] writes:

On Feb 19, 2006, at 2:18 PM, Josef ‘Jupp’ SCHUGT wrote:

I understand that you rather seek for a program but … hand-made
Sudoku are much more fun than those created by software. Up to now at
least.

This is slightly OT, so I’ll only offer this one contribution…
There is no such thing as hand-made sudoku puzzles at this point.
Yes, some newspapers still make the claim, but it’s simply untrue.

They could, but of course you can’t tell if they do…

Hi!

At Mon, 20 Feb 2006 12:53:50 +0900, Meino Christian C. wrote: