help in solving a difficult sudoku

Advanced methods and approaches for solving Sudoku puzzles

Postby Wolfgang » Thu Aug 04, 2005 10:00 am

sorry then
(read the fucking manual)
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Joined: 22 June 2005

Postby Wolfgang » Thu Aug 04, 2005 10:06 am

SteveF wrote:It is then possible to eliminate 6 from r3c5 based on colours, using the chain r6c5, r6c9, r4c7, r3c7).

Found it now, but can you explain this step, please?
Ooh, bad day, its easy, excuse me again:(
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Joined: 22 June 2005

Postby hana somekh » Thu Aug 04, 2005 10:41 am


Thank you for that !
After having tried and tested the 6's swordfish, I can finally find the logic in the method you proposed to finishing the puzzle !

I did not know that such a combination of swordfish could exist, I had previously understood that 2 or 3 digit possibilities in a single row/column must have EACH a corresponding possibility in column/row, before a swordfish could exist and only then eliminate all other possibilities of those rows and columns.

In this case, I thought that r1c4 must have been a part of the swordfish for their to be a swordfish in the first place ! -- which is why I could not see a visible swordfish - but now I know differently !!

Yet again -- something new learnt !!
hana somekh
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Joined: 30 July 2005


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