inferior puzzles thread

Everything about Sudoku that doesn't fit in one of the other sections

Postby tarek » Sat Mar 25, 2006 4:50 pm

What........

It is good that you provided the diagram to illustrate my my misconception.....

I now understand what you men by merging them together.......

so back to the solver for some fixes...

[Edit: I have now fixed the problem]

This is a 28-clue 4-stepper Empty centre boxe, rotational & diagonal reflective symmetry ( a 6 in the centre would turn it to a 3 stepper, but that will not please vidar:D )
Code: Select all
 . 7 . | . . 8 | 6 . . 
 9 . 5 | . . 4 | 3 . . 
 . 1 . | . . 3 | . 4 8 
-------+-------+------
 . . . | . . . | 7 3 9 
 . . . | . . . | . . . 
 1 9 4 | . . . | . . . 
-------+-------+------
 8 3 . | 9 . . | . 2 . 
 . . 6 | 2 . . | 8 . 4 
 . . 9 | 5 . . | . 6 . 


Tarek
User avatar
tarek
 
Posts: 2622
Joined: 05 January 2006

Postby Ocean » Sat Mar 25, 2006 7:34 pm

Three 22-steppers.

Code: Select all
 Ocean #3 (22 steps)
+-------+-------+-------+
| . . . | . 5 . | 2 4 1 |
| . . . | 9 . . | 6 . . |
| . . . | . 7 1 | . . . |
+-------+-------+-------+
| 9 7 . | . . . | 3 6 . |
| 2 . . | . . . | . . 9 |
| . 1 6 | . . . | . 2 8 |
+-------+-------+-------+
| . . . | 7 1 . | . . . |
| . . 4 | . . 3 | . . . |
| 5 9 7 | . 2 . | . . . |
+-------+-------+-------+


 Ocean #4 (22 steps)
+-------+-------+-------+
| 7 . . | 3 . 8 | . 5 . |
| . 9 . | . . . | . 2 . |
| . . . | 5 . 9 | . . . |
+-------+-------+-------+
| 5 . . | . 6 . | 4 . 7 |
| . . . | 4 . 1 | . . . |
| 3 . 4 | . 7 . | . . 6 |
+-------+-------+-------+
| . . . | 7 . 4 | . . . |
| . 3 . | . . . | . 9 . |
| . 5 . | 2 . 6 | . . 8 |
+-------+-------+-------+


 Ocean #5 (22 steps)
+-------+-------+-------+
| 7 . . | . 2 . | . . . |
| . . . | 6 . . | 5 . 4 |
| . . . | 7 . . | 2 . . |
+-------+-------+-------+
| . . . | 1 . 7 | 9 . . |
| 9 . . | . . . | . . 3 |
| . . 6 | 4 . 2 | . . . |
+-------+-------+-------+
| . . 5 | . . 6 | . . . |
| 8 . 4 | . . 5 | . . . |
| . . . | . 7 . | . . 8 |
+-------+-------+-------+
Ocean
 
Posts: 442
Joined: 29 August 2005

Postby vidarino » Sat Mar 25, 2006 7:42 pm

A few more 3-steppers, one of which is particularly nice to look at:

Code: Select all
+-------+-------+-------+
| . . . | 9 8 2 | . . . |
| . 2 1 | . . . | 7 8 . |
| . 5 . | . . . | . 4 . |
+-------+-------+-------+
| 9 . . | . 7 . | . . 5 |
| 1 . . | 3 6 8 | . . 2 |
| 6 . . | . 5 . | . . 1 |
+-------+-------+-------+
| . 1 . | . . . | . 6 . |
| . 8 3 | . . . | 5 1 . |
| . . . | 5 1 4 | . . . |
+-------+-------+-------+

+-------+-------+-------+
| . . 7 | . . . | 9 . . |
| . . . | 6 5 8 | . . . |
| 5 . 3 | . . . | 6 . 4 |
+-------+-------+-------+
| . 1 . | 2 . 5 | . 7 . |
| . 5 . | . 3 . | . 6 . |
| . 6 . | 4 . 9 | . 8 . |
+-------+-------+-------+
| 9 . 1 | . . . | 2 . 7 |
| . . . | 1 4 7 | . . . |
| . . 6 | . . . | 5 . . |
+-------+-------+-------+

+-------+-------+-------+
| 5 6 . | . . . | . 2 4 |
| 8 . . | . . . | . . 7 |
| . . 2 | 1 . 6 | 5 . . |
+-------+-------+-------+
| . . 1 | . 4 . | 7 . . |
| . . . | 3 1 7 | . . . |
| . . 9 | . 5 . | 3 . . |
+-------+-------+-------+
| . . 5 | 4 . 9 | 8 . . |
| 2 . . | . . . | . . 6 |
| 9 7 . | . . . | . 3 1 |
+-------+-------+-------+


And in the other end of the inferiority scale, two 26-steppers:

Code: Select all
+-------+-------+-------+
| . . 4 | . . 3 | . . 1 |
| 7 . . | 6 . . | . . . |
| . . 2 | 8 . . | . . . |
+-------+-------+-------+
| 3 . . | . 4 . | 8 5 . |
| . 7 . | . . . | . 9 . |
| . 2 8 | . 5 . | . . 3 |
+-------+-------+-------+
| . . . | . . 2 | 9 . . |
| . . . | . . 6 | . . 7 |
| 1 . . | 5 . . | 3 . . |
+-------+-------+-------+

+-------+-------+-------+
| 8 . . | . 3 . | . . . |
| . 2 . | . . 5 | . . . |
| . . 3 | 8 . . | . 9 2 |
+-------+-------+-------+
| 4 . . | . 2 . | 1 . 8 |
| . . . | . 4 . | . . . |
| 7 . 9 | . 1 . | . . 5 |
+-------+-------+-------+
| 9 7 . | . . 6 | 2 . . |
| . . . | 7 . . | . 4 . |
| . . . | . 8 . | . . 9 |
+-------+-------+-------+


Vidar
vidarino
 
Posts: 295
Joined: 02 January 2006

Postby Ruud » Sat Mar 25, 2006 8:20 pm

Heh, this thread has taken a U-turn into another interesting direction.

Here is a 4-Stepper with only 24 clues. And yes, it is minimal symmetric.
Code: Select all
. . .|7 1 .|. 3 .
3 . .|. . .|. 2 .
2 9 .|6 . .|. . .
-----+-----+-----
1 . 2|3 . .|. . 9
. . .|. . .|. . .
4 . .|. . 8|5 . 7
-----+-----+-----
. . .|. . 9|. 6 8
. 7 .|. . .|. . 1
. 3 .|. 4 5|. . .


And a 22-Clue 5-Stepper:
Code: Select all
. . .|. . .|6 8 .
2 . .|3 7 .|. . .
. . .|9 . .|. 5 .
-----+-----+-----
. . 4|7 . .|. . 3
. 8 .|. . .|. 1 .
6 . .|. . 5|4 . .
-----+-----+-----
. 7 .|. . 2|. . .
. . .|. 5 6|. . 9
. 1 3|. . .|. . .


Who's next?:D

Ruud.
Ruud
 
Posts: 664
Joined: 28 October 2005

Postby ab » Sun Mar 26, 2006 12:24 am

Ruud wrote:Heh, this thread has taken a U-turn into another interesting direction.


Ruud.


Yeah just when I'm beginning to find my feet with 20 step puzzles:
Code: Select all
96.|...|.34
2..|...|..6
...|47.|...
-----------
..7|8..|...
..8|.5.|3..
...|..2|9..
-----------
...|.93|...
4..|...|..8
65.|...|.93
ab
 
Posts: 451
Joined: 06 September 2005

Postby tarek » Sun Mar 26, 2006 1:18 am

2 puzzles 28 clues & require only 3 steps:
Code: Select all
 . . . | 9 . 6 | 4 . . 
 . . 1 | 2 5 . | . . . 
 7 . . | . . . | . 6 . 
-------+-------+------
 6 . . | . 1 . | . 8 4 
 . 1 . | 6 . 8 | . 5 . 
 9 4 . | . 3 . | . . 7 
-------+-------+------
 . 7 . | . . . | . . 9 
 . . . | . 6 7 | 3 . . 
 . . 5 | 1 . 4 | . . . 

 . 8 7 | . . . | . . . 
 . . . | 9 . 3 | . . 7 
 . . 6 | . . 8 | 3 . 1 
-------+-------+------
 . 6 5 | . 1 . | . 2 . 
 . . . | 7 . 2 | . . . 
 . 1 . | . 5 . | 9 7 . 
-------+-------+------
 2 . 8 | 5 . . | 4 . . 
 9 . . | 8 . 6 | . . . 
 . . . | . . . | 2 3 .


This is a 20-stepper (3,5,1,1,1,1,2,1,1,2,2,2,1,2,5,6,6,8,4,1)
Code: Select all
 . . . | . 4 . | . 6 . 
 3 . . | 8 . . | 7 . . 
 . . 4 | . 5 . | 2 . . 
-------+-------+------
 . . 5 | . . . | . 8 . 
 1 . 2 | 5 . 4 | 6 . 3 
 . 6 . | . . . | 4 . . 
-------+-------+------
 . . 7 | . 9 . | 5 . . 
 . . 3 | . . 1 | . . 6 
 . 8 . | . 2 . | . . .


Tarek
User avatar
tarek
 
Posts: 2622
Joined: 05 January 2006

Postby JPF » Sun Mar 26, 2006 1:37 pm

vidarino wrote:A few more 3-steppers, one of which is particularly nice to look at:
.......

Vidarino,
I’m a bit confused…
After the U-turn, do the puzzles have to be minimal and how ?

This one is not :
Code: Select all
+-------+-------+-------+
| . . . | 9 8 2 | . . . |
| . 2 1 | . . . | 7 8 . |
| . 5 . | . . . | . 4 . |
+-------+-------+-------+
| 9 . . | . 7 . | . . 5 |
| 1 . . | 3 6 8 | . . 2 |
| 6 . . | . 5 . | . . 1 |
+-------+-------+-------+
| . 1 . | . . . | . 6 . |
| . 8 3 | . . . | 5 1 . |
| . . . | 5 1 4 | . . . |
+-------+-------+-------+
You can remove r3c8 and r7c2 and get this one :
Code: Select all
 . . . | 9 8 2 | . . .
 . 2 1 | . . . | 7 8 .
 . 5 . | . . . | . . .
-------+-------+-------
 9 . . | . 7 . | . . 5
 1 . . | 3 6 8 | . . 2
 6 . . | . 5 . | . . 1
-------+-------+-------
 . . . | . . . | . 6 .
 . 8 3 | . . . | 5 1 .
 . . . | 5 1 4 | . . .
which is still nice, but :

6 steps : 13,7,11,8,8,7 ; more minimal:) , but not minimal:( .

The following one is only 8 steps : 12,9,7,4,5,8,6,5, after removing r1c7,r9c3 & r3c7,r7c3 which is non minimal...


Same thing for the third one : you can remove r1c9,r9c1 & r3c6,r7c4 but it does’nt qualify for the game.
:DThanx for your comments.
JPF
JPF
2017 Supporter
 
Posts: 3752
Joined: 06 December 2005
Location: Paris, France

Postby JPF » Sun Mar 26, 2006 2:20 pm

Here are 4-steppers “minimal symmetric” but not minimal.
Code: Select all
.  . . | 2 . . | 7 . 6
 . 8 . | . . . | . 1 5
 . . 5 | . 8 9 | . . .
-------+-------+-------
 6 . . | 9 2 . | . . .
 5 . 9 | . . . | 2 . 7
 . . . | . 1 5 | . . 3
-------+-------+-------
 . . . | 4 7 . | 8 . .
 8 2 . | . . . | . 3 .
 1 . 3 | . . 2 | . . .


4 steps : 10,15,17,11

Code: Select all
 8 . . | . . . | . 9 4
 . 4 . | . . . | . . 6
 . . . | 5 3 . | 1 2 .
-------+-------+-------
 7 . . | 4 1 . | . . .
 . . 5 | . 2 . | 8 . .
 . . . | . 6 3 | . . 9
-------+-------+-------
 . 3 9 | . 8 7 | . . .
 4 . . | . . . | . 3 .
 2 5 . | . . . | . . 7


4 steps : 13,20,15,6

Code: Select all
 9 . 8 | . . . | . . .
 . 5 . | 6 . . | 7 . 9
 . . . | 2 8 . | 5 . .
-------+-------+-------
 . 9 5 | . 2 . | . . 7
 2 . . | . . . | . . 6
 7 . . | . 4 . | 8 3 .
-------+-------+-------
 . . 7 | . 1 2 | . . .
 8 . 1 | . . 4 | . 7 .
 . . . | . . . | 2 . 3

4 steps : 14,12,19,8

We should try to find really minimal puzzles.

Who's next?:D

JPF
JPF
2017 Supporter
 
Posts: 3752
Joined: 06 December 2005
Location: Paris, France

Postby vidarino » Sun Mar 26, 2006 3:14 pm

JPF wrote:Vidarino,
I’m a bit confused…
After the U-turn, do the puzzles have to be minimal and how ?

This one is not :
...


Sorry, I guess I should have been a bit clearer. All the puzzles in question are all-axis (vertically, horizontally and diagonally) symmetric, and minimal as such. But if you "demote" them to 180 degree symmetry, they aren't minimal anymore, quite true.
vidarino
 
Posts: 295
Joined: 02 January 2006

Postby Ocean » Sun Mar 26, 2006 7:15 pm

Two candidates:
Code: Select all
  Ocean #6 (25 steps)
+-------+-------+-------+
| . . 1 | 2 3 4 | . . . |
| . 5 . | 1 . . | . . . |
| 2 6 . | . . . | . . . |
+-------+-------+-------+
| 7 8 . | . . . | . 2 . |
| . . 9 | 8 . 7 | 3 . . |
| . 2 . | . . . | . 7 5 |
+-------+-------+-------+
| . . . | . . . | . 5 3 |
| . . . | . . 3 | . 8 . |
| . . . | 9 8 5 | 4 . . |
+-------+-------+-------+


  Ocean #7 (23 steps)
+-------+-------+-------+
| . . . | 3 . . | 2 . . |
| . . . | 8 . 7 | . . 4 |
| . . . | . 9 . | 6 . 5 |
+-------+-------+-------+
| 9 3 . | . . . | 8 . . |
| . 7 6 | . . . | 5 4 . |
| . . 4 | . . . | . 3 2 |
+-------+-------+-------+
| 2 . 5 | . 7 . | . . . |
| 1 . . | 4 . 5 | . . . |
| . . 3 | . . 9 | . . . |
+-------+-------+-------+
Ocean
 
Posts: 442
Joined: 29 August 2005

Postby Ocean » Mon Mar 27, 2006 10:37 pm

These two are both symmetric and minimal sudokus in the ordinary sense (if any clue is removed the sudoku is invalid).

Code: Select all
(Minimal 21-stepper)
+-------+-------+-------+
| 9 . . | . . . | 5 4 2 |
| 2 1 . | . . . | 9 . . |
| . . 4 | . . . | . . 8 |
+-------+-------+-------+
| . . . | 8 4 1 | . . . |
| . . . | . 2 . | . . . |
| . . . | 3 7 6 | . . . |
+-------+-------+-------+
| 4 . . | . . . | 8 . . |
| . . 7 | . . . | . 1 3 |
| 6 2 8 | . . . | . . 7 |
+-------+-------+-------+

(Minimal 20-stepper)
+-------+-------+-------+
| . . . | . . . | 1 . . |
| 4 . . | . . 8 | 7 3 . |
| 2 . 5 | 9 . . | . . . |
+-------+-------+-------+
| 5 . . | . . . | . 6 . |
| . 8 . | . . . | . 2 . |
| . 4 . | . . . | . . 5 |
+-------+-------+-------+
| . . . | . . 7 | 2 . 3 |
| . 5 6 | 4 . . | . . 1 |
| . . 3 | . . . | . . . |
+-------+-------+-------+
Ocean
 
Posts: 442
Joined: 29 August 2005

Postby JPF » Mon Mar 27, 2006 11:52 pm

Ocean wrote:These two are both symmetric and minimal sudokus in the ordinary sense (if any clue is removed the sudoku is invalid).

Nice !
one more :
Code: Select all
 (Minimal 20-stepper)


 . . . | . . 7 | 6 8 4
 . . . | 1 . 3 | . 9 .
 . . . | . 4 . | 1 . .
-------+-------+-------
 7 . 6 | . . 5 | . . 3
 . . . | . . . | . . .
 5 . . | 7 . . | 8 . 2
-------+-------+-------
 . . 1 | . 5 . | . . .
 . 7 . | 4 . 2 | . . .
 9 2 3 | 8 . . | . . .


JPF
JPF
2017 Supporter
 
Posts: 3752
Joined: 06 December 2005
Location: Paris, France

Postby JPF » Tue Mar 28, 2006 12:59 am

:?: I'd like to make an observation.

It seems to be impossible to find a puzzle starting with singles only, until n cells are known and stopping after, for 70 < n < 81.
Does anybody have an explanation for that ?
or is it not true ?

JPF
JPF
2017 Supporter
 
Posts: 3752
Joined: 06 December 2005
Location: Paris, France

Postby JPF » Tue Mar 28, 2006 11:58 pm

For the road :

Code: Select all
 21-stepper


 . . . | . 3 . | 6 . 8
 2 . . | . . 8 | 5 . .
 . . 9 | . . . | . . 1
-------+-------+-------
 . 5 . | . 2 . | 8 . .
 . 6 . | 4 . 3 | . 2 .
 . . 2 | . 8 . | . 6 .
-------+-------+-------
 1 . . | . . . | 7 . .
 . . 8 | 1 . . | . . 4
 7 . 4 | . 9 . | . . .


21 steps : (3,1,1,1,1,2,3,1,2,1,4,1,1,2,2,4,7,5,7,5,1)
180°- symmetric minimal ; not abs. minimal



and
Code: Select all
4 steps - 27 clues


 . . 3 | . . 7 | . . 8
 . . 1 | 4 . . | . . .
 2 7 6 | . . . | . . 4
-------+-------+-------
 5 . . | . 4 . | . . .
 . . 8 | 1 7 9 | 6 . .
 . . . | . 2 . | . . 1
-------+-------+-------
 6 . . | . . . | 9 1 7
 . . . | . . 6 | 5 . .
 8 . . | 5 . . | 3 . .


4 steps : (12,16,15,11)
JPF
2017 Supporter
 
Posts: 3752
Joined: 06 December 2005
Location: Paris, France

Postby Jo88 » Wed Mar 29, 2006 1:32 am

Nice puzzle Tarek:D Like it !

. . . | . 2 . | . 9 .
. . 8 | 9 . 1 | 7 . 6
. 3 . | 6 . . | . 5 .
~~~~~~~~~~~
. 1 6 | . . . | . 8 .
3 . . | . . . | . . 9
. 8 . | . . . | 4 7 .
~~~~~~~~~~~
. 2 . | . . 3 | . 1 .
4 . 3 | 2 . 5 | 8 . .
. 7 . | . 6 . | . . .

Solves nicely in http://kinabaloo.com/relax/sudoku.html

Jo
Jo88
 
Posts: 12
Joined: 22 March 2006

PreviousNext

Return to General