Grids with minimal UA18s for all 2-row,2-col,2-digit UA sets

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Re: Grids with minimal UA18s for all 2-row,2-col,2-digit UA

Postby champagne » Sun Jul 21, 2019 2:43 am

The scan of solution grids producing 18 clues puzzles having a band with 2 clues is closed and produced 106 puzzles, only 3 more than the known by coloin.
Ill published later to-day the list of puzzles with more comments
champagne
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fres 18 band 2 uas good and bad news

Postby champagne » Sun Jul 21, 2019 7:10 am

The good new is that the run produced 8 new 18 having a band with 2 clues
Hidden Text: Show
Code: Select all
.....6..............9........7..8.5..6...3.4.......1..3...1.6....5.9...8.4.5....7
........9..............1....1...4...3....2..8.9......65..6..3....29...1...8.7..4.
........9..............1....1...4...3....7..89.......6..29...1...7.2..4.8..6..3..
.....6..............9.......3...7.5........1...8..2.9...41....8.1.9..6...7..4...3
.....6..............9.......3...7.5........1...8..2.9...21....8.1.9..6...7..4...3
......7..............2.....2...4...55....3.....8.7.1...1.8..9...6.5....2.7.....4.
..3......................6.2....5.9......8..2..73...4.5...2......4.9...39...6...8
....5..............8........3......8.6..1...3..7.6...2...9..4....2..8.9...5..3.1.


The bad new is that some known are missing although they have been processed successfully in check mode.
As I worked in slices, I restart the process in once to see if I made a handling error.
But it can be a bug!!!
champagne
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Re: Grids with minimal UA18s for all 2-row,2-col,2-digit UA

Postby champagne » Mon Jul 22, 2019 7:34 am

It was a bug in the entry file generator.
The 5 missing 18 are now there, no fresh 18 came.

So at the end

the total number of 18 clues puzzles having 2 clues in a band is 111
103 known by coloin
8 more found here

I am nearly sure that this is now a bug free result.

The (dirty) corresponding code will be as process 500 in my skmppv2 next repository update.
I did not check that they all are minimal, but I'll do it to be safe. Assuming that they are minimal, we have here a code directly proving that no 17 clues puzzles having 2 clues in a band can be produced.

And more important for me, I have now some potential to speed up the 17 clues search. I started the corresponding implementation. I could have some ideas of the improvement potential (if any) within 2 weeks.
champagne
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Re: Grids with minimal UA18s for all 2-row,2-col,2-digit UA

Postby blue » Tue Jul 23, 2019 3:12 pm

Hi champagne,

champagne wrote:I am nearly sure that this is now a bug free result.

I can confirm the count of 111.

champagne wrote:And more important for me, I have now some potential to speed up the 17 clues search. I started the corresponding implementation. I could have some ideas of the improvement potential (if any) within 2 weeks.

champagne, in other thread, wrote:Good challenge. So far I have nothing to do that, but after the results of the search of 18s having a band with 2 clues I see
a possible alternative design for the 17 clues search, this is for to-morrow
a possible design to explore a solution grid in the area 18-20 if the first idea works

Good luck, and have fun :!:
Blue.
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Re: Grids with minimal UA18s for all 2-row,2-col,2-digit UA

Postby champagne » Wed Jul 24, 2019 6:32 am

Hi blue,
Thank you first for confirmation.

Regarding the next variant of things you have done, as the main change in in the "valid XY" generator, I should have enough code tested in 2 or 3 weeks (not that much time to spend on this project currently) to have a better view of the validity of my positive feeling. As all test have to be re run, I'll change also things in the "phase 2", but nothing important
champagne
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