The New Sudoku Players' Forum

Sponsored by Enjoy Sudoku

Skip to content

Puzzles with 123456789 in the diagonal

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

Re: More Homework 2

Postby marek stefanik » Sat Feb 19, 2022 10:20 pm

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

Proof that the first 29 cells are optimal: Show
b1p159 given
r1c23456 highest possible values (below shortened to HPVs)
r1c7 – 4 impossible (any of r1c123 could be filled as a NS, thus would be redundant), therefore 3 is the HPV
r1c89 – would make 9 or 8 in r1 (in that order) a HS, hence redundant as a given
r2c134 HPVs
r2c56 – with PC 4b1\r3 HP 34b2, if 4 were given then r2c2 could be filled with HT 679b3p789, PC 5b3\r2, NS r2c2, hence would be redundant, 3. HPVs
r2c789 – corresponding given in r1 would be redundant (HS)
r3c1 HPV
r3c2 cannot be given (FH b1)
r3c456789 – corresponding given in b1 would be redundant (HS)
r4c1 HPV
r4c2 – corresponding given in b1 would be redundant (HS)

Marek
marek stefanik
 
Posts: 360
Joined: 05 May 2021
Top

Re: More Homework 2

Postby coloin » Sat Feb 19, 2022 10:37 pm

I think the first 15 are optimal ..as this is approaching my best
Code: Select all
+---+---+---+
|198|765|3..|
|726|93.|...|
|5.3|...|...|
+---+---+---+
|9..|427|.1.|
|3..|.5.|...|
|..7|..6|...|
+---+---+---+
|...|..9|7..|
|...|...|.8.|
|2..|...|..9|
+---+---+---+

a space has to be at r4c2 ... r4c3 can be a 7
coloin
 
Posts: 2502
Joined: 05 May 2005
Location: Devon
Top

Re: More Homework 2

Postby marek stefanik » Sun Feb 20, 2022 12:58 am

This should be the best one:
Code: Select all
+-------+-------+-------+
| 1 9 8 | 7 6 5 | 3 . . |
| 7 2 6 | 9 3 . | . . . |
| 5 . 3 | . . . | . . . |
+-------+-------+-------+
| 9 . 7 | 4 8 . | 6 5 . |
| 8 . . | 3 5 . | . . 7 |
| . . . | . . 6 | . . . |
+-------+-------+-------+
| . . . | . 1 . | 7 . . |
| . . . | . . . | . 8 . |
| . . . | . . . | . 6 9 |
+-------+-------+-------+


Marek
marek stefanik
 
Posts: 360
Joined: 05 May 2021
Top

Re: More Homework 2

Postby coloin » Sun Feb 20, 2022 12:05 pm

Yes that is the max , well done for showing that there cant be bigger clues in the first band ..... and the 3 at r5c4 is the largest clue possible
.. then add 3 more clues to give your puzzle.

Relabelling this puzzle to max lex representation presumably we have the answer to the max lex puzzle with the diagonal clues question
[2B1]
Code: Select all
+---+---+---+        +---+---+---+                           
|987|654|3..|        |987|654|3..|                           
|625|83.|...|        |652|73.|...|                           
|4.3|...|...|        |43.|...|...|                           
+---+---+---+        +---+---+---+                           
|8.6|17.|54.|        |8..|34.|..6|                           
|7..|34.|..6|        |76.|18.|54.|                           
|...|..5|...|        |...|..5|...|                           
+---+---+---+        +---+---+---+                           
|...|.9.|6..|        |...|.9.|6..|                           
|...|...|.7.|        |...|...|.8.|                           
|...|...|.58|        |...|...|.57|                           
+---+---+---+        +---+---+---+      edit - larger isomorph 30 clues

Last edited by coloin on Sun Feb 20, 2022 5:46 pm, edited 1 time in total.
coloin
 
Posts: 2502
Joined: 05 May 2005
Location: Devon
Top

Re: More Homework 2

Postby marek stefanik » Sun Feb 20, 2022 3:19 pm

2B1, 2A (32 clues)
Code: Select all
+-------+-------+-------+
| 9 8 7 | 6 5 4 | 3 . . |
| 6 5 4 | 3 2 . | . . . |
| 3 . 2 | . . . | . . . |
+-------+-------+-------+
| 8 . 9 | 7 4 5 | 6 . . |
| 7 . 6 | . 8 . | 9 . . |
| . . 5 | . . 6 | . . . |
+-------+-------+-------+
| . . . | . . . | 1 . . |
| . . . | 8 . . | . 4 9 |
| . . . | . . . | . 7 3 |
+-------+-------+-------+

Edit: Given the top band, r6c6 must be 6 (14 impossible, 3 would make 3 in b2 redundant, 8 would make 8 in b1 redundant).
Edit2: It should be the best puzzle possible for 2B1.

Marek
marek stefanik
 
Posts: 360
Joined: 05 May 2021
Top

Re: More Homework 2

Postby coloin » Sun Feb 20, 2022 6:00 pm

Excellent
It shows understanding the minimality issue makes for easier getting to the maximum [unlike my crude methods !]
cut to the chase, my best for
2B3
Code: Select all
+---+---+---+     +---+---+---+
|1..|987|63.|     |1..|987|63.|
|.2.|63.|95.|     |.2.|64.|9..|
|..3|5..|8..|     |..3|1..|...|
+---+---+---+     +---+---+---+
|987|4..|56.|     |.6.|4..|...|
|4.6|.5.|...|     |2..|.5.|8..|
|..5|..6|...|     |...|..6|...|
+---+---+---+     +---+---+---+
|..2|3..|7..|     |.4.|...|7..|
|...|...|.8.|     |...|...|.8.|
|...|...|..9|     |..1|8..|..9|
+---+---+---+     +---+---+---+     sigh , edit improved


coloin
 
Posts: 2502
Joined: 05 May 2005
Location: Devon
Top

Re: More Homework 2

Postby marek stefanik » Wed Feb 23, 2022 8:43 am

Speaking of crude methods...
I was wondering why this one was taking longer than a few minutes... the search got stuck on a DP:
Hidden Text: Show
Code: Select all
+-------+-------+-------+
| 1 . . | 9 8 7 | 6 3 . |
| . 2 . | 6 4 . | 9 5 . |
| . . 3 | 5 . . | . . . |
+-------+-------+-------+
| 9 8 7 | 4 . . | 5 6 . |
| . . . | . 5 . | . . . |
| . . . | . . 6 | . . . |
+-------+-------+-------+
| . . . | . . . | 7 . . |
| . . . | . . . | . 8 . |
| . . . | . . . | . . 9 |
+-------+-------+-------+
3b2, 12b2, 12b3, 12r4, UR12r34c56
And went on to check every minimal subpuzzle from here...


Anyway, having fixed that this should be the best you can get:
Code: Select all
+-------+-------+-------+
| 1 . . | 9 8 7 | 6 3 . |
| . 2 . | 6 4 . | 9 5 . |
| . . 3 | 5 . . | . . . |
+-------+-------+-------+
| 9 8 7 | 4 . . | 5 . . |
| 4 6 . | . 5 . | . 7 . |
| . . . | . . 6 | . . . |
+-------+-------+-------+
| . . . | 1 . . | 7 . . |
| . . . | . . . | . 8 . |
| 2 . . | . . . | . . 9 |
+-------+-------+-------+


Marek
marek stefanik
 
Posts: 360
Joined: 05 May 2021
Top

Re: More Homework 2

Postby JPF » Wed Feb 23, 2022 8:05 pm

1A
Code: Select all
+---+---+---+
|1..|.9.|...|
|.2.|.7.|...|
|..3|...|.6.|
+---+---+---+
|...|4..|.3.|
|7..|.5.|1..|
|...|..6|...|
+---+---+---+
|...|.1.|7..|
|..4|...|.8.|
|..6|...|..9|
+---+---+---+    18 clues

JPF
JPF
2017 Supporter
 
Posts: 6139
Joined: 06 December 2005
Location: Paris, France
Top

Re: More Homework 2

Postby coloin » Wed Feb 23, 2022 9:37 pm

Well done in finding the 18 ..... there are only half a dozen more I believe !
coloin
 
Posts: 2502
Joined: 05 May 2005
Location: Devon
Top

Re: More Homework 2

Postby JPF » Thu Feb 24, 2022 6:06 pm

coloin wrote:there are only half a dozen more I believe !
maybe.
It takes time to find them.
Here is an other one:
Code: Select all
+---+---+---+
|1..|.8.|...|
|.2.|...|..6|
|..3|...|..4|
+---+---+---+
|...|4..|...|
|78.|.5.|1..|
|...|..6|...|
+---+---+---+
|...|.1.|7..|
|...|...|.8.|
|..6|..2|..9|
+---+---+---+    18 clues

JPF
JPF
2017 Supporter
 
Posts: 6139
Joined: 06 December 2005
Location: Paris, France
Top

Re: More Homework 2

Postby JPF » Sun Feb 27, 2022 7:11 pm

Last proposal:

3B
Code: Select all
based on Pattern game 438
+---+---+---+
|1..|...|..5|
|.2.|9..|8..|
|..3|.8.|.7.|
+---+---+---+
|.6.|4..|...|
|..2|.5.|3..|
|5..|..6|.1.|
+---+---+---+
|.4.|.2.|7..|
|..6|..7|.8.|
|...|3..|..9|
+---+---+---+  ED=10.6/10.6/10.6

1A
Code: Select all
+---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+
|1..|.9.|...|   |1..|.8.|...|   |1..|...|...|   |1..|.2.|...|   |1..|...|4..|
|.2.|.7.|...|   |.2.|...|..6|   |.2.|.7.|...|   |.2.|.7.|...|   |52.|...|...|
|..3|...|.6.|   |..3|...|..4|   |..3|8..|.6.|   |..3|...|.6.|   |..3|..9|..6|
+---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+
|...|4..|.3.|   |...|4..|...|   |..8|4..|...|   |...|4..|.3.|   |...|4..|...|
|7..|.5.|1..|   |78.|.5.|1..|   |...|.5.|1.2|   |7..|.5.|2..|   |7..|.5.|1..|
|...|..6|...|   |...|..6|...|   |...|..6|...|   |...|..6|...|   |...|..6|...|
+---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+
|...|.1.|7..|   |...|.1.|7..|   |...|.1.|7..|   |...|...|7.5|   |...|.1.|7..|
|..4|...|.8.|   |...|...|.8.|   |..4|...|.8.|   |..4|3..|.8.|   |...|.7.|.8.|
|..6|...|..9|   |..6|..2|..9|   |..6|...|..9|   |...|...|..9|   |..6|...|..9|
+---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+   +---+---+---+    18 clues

JPF
JPF
2017 Supporter
 
Posts: 6139
Joined: 06 December 2005
Location: Paris, France
Top

Answers

Postby coloin » Thu Mar 10, 2022 11:43 pm

1A
Code: Select all
1.....3...2..8......3...4.....4.7....9..5...2.....6...4..3..7.........8.....2...9
1.....6...2..8......3...4.....4......98.5...2.....6...4..3..7.........8.....2...9
1.....6...2..8......3...4.....4......98.5...2.....6...6..1..7.........8.....2...9
1.....6...2..8......3.9.......4..1...9..5...2.....6...4.....7..6......8.....2...9
1.....3...2..9......3...4....84......9..5...2...7.6.....43..7.........8.........9

2 more ... giving 7 in total found ...
Code: Select all
1.........25........37..4.....4......9..5...2...1.6...4.....7....7....8.....2...9
1...9.4...2...5.....3.........4......9..5...2.....6.....43.17.........86........9


1B
two minimal 36s
Code: Select all
1....342.42.71.3....32.....6.142.95..4.15.........6...51.8..73.3.4.7..8.27..315.9
1....342.42.71.3....32.....6.142.95..4.15.........6...51.8..73.3.4.7..8.27..3.549


1C
That 10.6 diamond is plenty good enough !

Filtered from the hardest database however were these two
Code: Select all
1....8....2...5.3...3.2.1.....4.....3...5..2..7...64...9....7..5...1..8...6.....9 ED=11.4/1.2/1.2
1..26..7..2.8..1....3..1......4...5...4.5...78....63..6....27...92....8...7.....9 ED=11.2/11.2/11.0
coloin
 
Posts: 2502
Joined: 05 May 2005
Location: Devon
Top
Previous
Post a reply

Return to General

Powered by phpBB® Forum Software © phpBB Group

phpBB SEO