The New Sudoku Players' Forum

[aleph]

Started to play with Sudoku 2 weeks ago.
The last Sunday Times publish a Sudoku classified as "Superior"....

a) is this the same as fiendish? I solved a couple but this seems to have new challenge types...

b) have been really fighting with it... so just wanted to be sure: can each number be found by "pure" deduction (i.e. conflict resolution) or are there some puzzles where you have to try one of of possibilities and see if it fails somewhere (seems to me this is not the "good way" to do it...

Concretly in the 31st puzzle have added only 7 numbers and am stuck finding an "hint" that allows me to break all the apparently circular dependencies

TIA

[Anette]

Could you post the grid?

I can't find it on timesonline.

/Anette

[aleph]

here it goes

***|985|***
*9*|1*6|*8*
**5|***|6**
----+----+----
*19|***|73*
**3|***|2**
*82|***|95*
----+---+---
**7|***|1**
*5*|4*1|*2*
***|392|***

[scrose]

This puzzle is already being discussed in this thread.

[jonah]

I too have done Feindish but am stumped by the Superior in Sunday Times 31st July!
I got 7 numbers also (4,8,4,4,9,8,7) within a few minutes but since then have been unable to progress further, despite spending up to an hour each day looking at it. I have checked the solution on this web site and my numbers are all correct. Seeing the solution is of no help: Does anyone know of a web site with a step by step solver?
Am I missing something

[simes]

Hi Jonah,

Yep, mine can solve one step at a time, and produce a log of the logic used.

Follow the link from the WWW button below.

Simes

PS, here's the log from after the first 7 numbers

Code: Select all

row 7: naked pair 56 in cells (7,4)(7,5) - updating candidates for cell(s) (7,1)(7,2)(7,8)(7,9)
row 3: hidden pair 19 in cells (3,8)(3,9) - removing other candidates for these cells
block 3: naked pair 19 in cells (3,8)(3,9) - updating candidates for cell(s) (1,8)(1,9)
block 2: row 3 must contain 7, removing 7 from candidates for cell(s) (3,2)
block 6: column 9 must contain 8, removing 8 from candidates for cell(s) (8,9)(9,9)
column 9: hidden triplet 257 in cells (1,9)(2,9)(9,9) - removing other candidates for these cells
block 3: column 7 must contain 3, removing 3 from candidates for cell(s) (8,7)
(8,7) = 8 : only possible value for this cell

[jonah]

Hi Simes. Thanks for your tips: Even with your solution, it took me half an hour to grasp the logic which leads to the key step. Is it really possible for the human brain to find the hidden 257 triple, unless you are looking for that one particular solution in advance? I don't think I would ever have found it. I have tried to use the same techniqu since but have not found an example yet.
I have downloaded your solver: Very impressive!
Thanks again

Regards Jonah

[The Druid]

Is it really possible for the human brain to find the hidden 257 triple, unless you are looking for that one particular solution in advance?

I think it must be possible... I solved this particular puzzle using my usual routine (read, "plodding") human-brain methods (I don't have a solving program).

And I didn't realise that there was supposed to be anything particularly difficult about it at the time. (Probably just as well, or I would have psyched myself up to fail!)

The Druid

[steve]

I saw a proposal from Simes regarding a hidden triple. However in my grid so far, in cell (1,9) I have the options 2,3,4,7 (since 6 and 8 given and cannot be 1 due to 1,9 pair in cells 3,8 and 3,9 and 5 given in row 1. In cell (2,9) I have the the options 2,3,5,7 and in (9,9) the options 4,5,6,7.
So I don't see the triple occurence of 2,5,7!

Could someone please put me out of my 8 day misery.

Thanks in grateful anticipation!

[simes]

I feel I should quote Yoda here, if only I could think of something appropriate. I'll have to make do with "you can't see the wood for the trees".

Look how many cells in column nine can contain any of 2, 5 or 7. If you've performed the previous eliminations correctly, you'll have three. Three cells, three candidates. Leaves no room for any other candidates, so some eliminations perform can you.

Hidden Triplet. Plain as a hidden thing can be.

Simes

[steve]

Thank you Simes - I now realise what a 'triple' is and of course have seen them many times before - I've just never used one (I don't think) to actually make eliminations!
Thanks again, Steve (a much happier man!)

[Karyobin]

Clear your mind.

Only when at peace you are, the triplet will you see. Always look you to the future, never your mind on where you are, what you are doing.

Rest now for the day, I shall. And rest you will too, when thirty-three years you reach mmmmmMMMMMM?!


(Sorry, simes inspired me)

[The Central Scrutinizer]

"Stella, I will enjoy."

[george-no1]

"Surreal, this conversation has become"

Funny how that only happened when Karyobin got involved.

G