puzzles/unfinished/divvy.c, branch master My sgt-puzzles tree Substantial reworking of Solo so that it implements both Sudoku-X 2008-04-07T15:56:42+00:00 Simon Tatham anakin@pobox.com 2008-04-07T15:56:42+00:00 93103eeca4e41ecaa874069b10f2a3de8c392435 (require both main diagonals to have one of every digit in addition to all the usual constraints) and Jigsaw Sudoku (replace the array of rectangular sub-blocks with the sub-blocks being random polyominoes). To implement the latter, I've moved my `divvy.c' library routine out of the `unfinished' subdirectory. Jigsaw mode is currently an undocumented feature: you enable it by setting the rows parameter to 1 (and the columns parameter to your desired grid size, which unlike normal Sudoku can be anything you like including a prime number). The reason it's undocumented is because generation times are not yet reliably short: sometimes generating a jigsaw-type puzzle can hang for hours and still get nowhere. (The algorithm should terminate in principle, but not in any time you're prepared to wait.) I _think_ I know how to solve this, but have yet to try it. Until then, jigsaw mode will remain a hidden feature. Printing of X-type puzzles is also substandard at present, because the current print-colour API replaces the desired light shading of the X-cells with heavy diagonal hatching. I plan to adjust the API imminently to address this. [originally from svn r7974] 
(require both main diagonals to have one of every digit in addition
to all the usual constraints) and Jigsaw Sudoku (replace the array
of rectangular sub-blocks with the sub-blocks being random
polyominoes). To implement the latter, I've moved my `divvy.c'
library routine out of the `unfinished' subdirectory.

Jigsaw mode is currently an undocumented feature: you enable it by
setting the rows parameter to 1 (and the columns parameter to your
desired grid size, which unlike normal Sudoku can be anything you
like including a prime number). The reason it's undocumented is
because generation times are not yet reliably short: sometimes
generating a jigsaw-type puzzle can hang for hours and still get
nowhere. (The algorithm should terminate in principle, but not in
any time you're prepared to wait.) I _think_ I know how to solve
this, but have yet to try it. Until then, jigsaw mode will remain a
hidden feature.

Printing of X-type puzzles is also substandard at present, because
the current print-colour API replaces the desired light shading of
the X-cells with heavy diagonal hatching. I plan to adjust the API
imminently to address this.

[originally from svn r7974]
A rigorous proof. Totally unimportant to the code, but I didn't want 2007-08-25T17:46:13+00:00 Simon Tatham anakin@pobox.com 2007-08-25T17:46:13+00:00 a603318eec298f1093139117fdc46097c745c293 to lose it :-) [originally from svn r7703] 
to lose it :-)

[originally from svn r7703]
Fix an inaccurate comment. 2007-08-25T15:50:33+00:00 Simon Tatham anakin@pobox.com 2007-08-25T15:50:33+00:00 f228c5ef004dc901c984133a34819794e90d66a1 [originally from svn r7702] 
[originally from svn r7702]
I've just realised that my deliberate avoidance of non-simply 2007-08-25T15:32:41+00:00 Simon Tatham anakin@pobox.com 2007-08-25T15:32:41+00:00 cb0901306de9b1698323823f0180f98c6bac7789 connected polyominoes actually causes a loss of generality for sufficiently large k. I hadn't previously noticed, because you need k to be (I think) at least 23 and none of my potential applications require anything nearly that large. Add some discussion of this. [originally from svn r7701] 
connected polyominoes actually causes a loss of generality for
sufficiently large k. I hadn't previously noticed, because you need
k to be (I think) at least 23 and none of my potential applications
require anything nearly that large. Add some discussion of this.

[originally from svn r7701]
Ahem. Finishing writing the comment _before_ checkin is generally sensible. 2007-08-18T13:32:56+00:00 Simon Tatham anakin@pobox.com 2007-08-18T13:32:56+00:00 4ff90bd47f4bd3b11c4fb8b1ea25afb7b95f76da [originally from svn r7694] 
[originally from svn r7694]
Allow a 1-omino to be completely destroyed and recreated in an 2007-08-18T13:30:13+00:00 Simon Tatham anakin@pobox.com 2007-08-18T13:30:13+00:00 4c1e3ca7cbefda5d25b26c83c9767c81682f5478 arbitrary unclaimed square. This cures the most common cause of generation failures (covering a large area in dominoes was the most difficult case, and would fail even if the large area was 1xn!); the failure rate is now sufficiently low under all circumstances I've found that I'm willing to just loop until I get a success. [originally from svn r7693] 
arbitrary unclaimed square. This cures the most common cause of
generation failures (covering a large area in dominoes was the most
difficult case, and would fail even if the large area was 1xn!); the
failure rate is now sufficiently low under all circumstances I've
found that I'm willing to just loop until I get a success.

[originally from svn r7693]
Better test-mode diagnostics. 2007-08-18T11:19:29+00:00 Simon Tatham anakin@pobox.com 2007-08-18T11:19:29+00:00 333d57bf6ec7def6fa78215a71a2d05476167fc1 [originally from svn r7691] 
[originally from svn r7691]
A piece of library code which constructs a random division of a 2007-08-18T10:07:29+00:00 Simon Tatham anakin@pobox.com 2007-08-18T10:07:29+00:00 cc54c09413a08ea150fd8cc6706ed61ccc8ce47e rectangle into equally sized ominoes. I have a couple of potential applications for this, but none I've actually implemented yet, so for the moment it's living in `unfinished'. [originally from svn r7690] 
rectangle into equally sized ominoes. I have a couple of potential
applications for this, but none I've actually implemented yet, so
for the moment it's living in `unfinished'.

[originally from svn r7690]