Calcudoku puzzle forum
https://www.calcudoku.org/forum/

Tues Sept 13 9 x 9
https://www.calcudoku.org/forum/viewtopic.php?f=16&t=1461
Page 1 of 1

Author:  eclipsegirl  [ Thu Sep 15, 2022 1:06 am ]
Post subject:  Tues Sept 13 9 x 9

I just wanted to congratulate the 97 people who solved it.
It was tough.

I loathe the particular pattern. It is the hardest of the various 9 x 9 patterns.
Its been a very long time since we have seen that pattern.

Author:  vittorio  [ Thu Sep 15, 2022 7:37 am ]
Post subject:  Re: Tues Sept 13 9 x 9

eclipsegirl wrote:
I just wanted to congratulate the 97 people who solved it.
It was tough.

I loathe the particular pattern. It is the hardest of the various 9 x 9 patterns.
Its been a very long time since we have seen that pattern.


At the beginning I was scared of the puzzle, when I saw the pattern and the difficulty level (121!), and I was absolutely stuck once filled the "obvious" cells. Every cage had multiple possible combination, especially the multiplication ones on the left (columns a, b, c, d).
At a certain point I remembered a way to approach the diagram not so common, which I had read in one of the introductions in the Patrick’s books: you can’t only use the “addition” tool (every column or row has 45 as sum of the first 9 numbers) but also the “multiplication” tool: every column or row has 1×2×3×4×5×6×7×8×9 = 9! as product of the first 9 numbers, so two columns have (9!)^2, three columns have (9!)^3 and so on. These are huge numbers, but getting the number of the first three columns (9!)^3 and dividing it by the three products in there and the other numbers already inserted, I got a “small” product that, divided in factors, gave me a smaller number of possible combinations for the remaining cells of the columns a, b, and c. Above all, combining the “multiplication” way with the “addition” one, I got very few possibilities for the two 3024× and 180×. Just two for the 3024× and two for 180×.
I put the two for 3024× randomly in both cages, but soon I understood that it was the wrong choice, so I inverted the two combination (at that point the 180× was unique) and went on. I can’t say that at this point it was “easy”, but at least it was more manageable… so, at the end I succeed within midnight of Tuesday! I couldn’t believe it (and I can’t believe it till now! [biggrin] )

Author:  pnm  [ Thu Sep 15, 2022 10:34 am ]
Post subject:  Re: Tues Sept 13 9 x 9

eclipsegirl wrote:
I loathe the particular pattern. It is the hardest of the various 9 x 9 patterns.
Its been a very long time since we have seen that pattern.


It sounds like we also need a "dislike" button next to the "+" :-)

(or even a "loathe" button [tongue] )

Author:  paulv66  [ Thu Sep 15, 2022 8:22 pm ]
Post subject:  Re: Tues Sept 13 9 x 9

Like eclipsegirl, I was somewhat apprehensive when I saw the pattern for this week’s puzzle. But, like vittorio, I used the multiplication approach. I found that the product of b2c2, b6b7, c4 and c6 must equal 11340. The only combination that worked for these cells was 73, 25, 6 and 9. That allowed me to fill in the left hand side of the puzzle.

I think I needed to do a similar calculation in relation to the right hand side. But the puzzle worked out without too many hitches. I did it in one go and it took me just under 30 minutes. I know that sounds like a long time to spend on one puzzle, but I doubt I solve many of the Tuesday 9x9s in less than that!

Author:  beaker  [ Thu Sep 15, 2022 11:21 pm ]
Post subject:  Re: Tues Sept 13 9 x 9

Patrick.....I have been thinking for the past week that we need a dislike button especially after today with the mod puzzle....too many cages with mod in them [cursing]

Author:  paulv66  [ Thu Sep 15, 2022 11:39 pm ]
Post subject:  Re: Tues Sept 13 9 x 9

beaker wrote:
Patrick.....I have been thinking for the past week that we need a dislike button especially after today with the mod puzzle....too many cages with mod in them [cursing]


I struggled with this one for quite a while. Only got it finished a few minutes ago, with about half an hour to spare before today’s deadline. [scared]

Page 1 of 1 All times are UTC + 1 hour [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/