dailysudoku.com

Clement · Posted: Mon Apr 05, 2010 11:36 pm Post subject: Apr 6 VH

Two steps.
After the W-Wing 47 in r38c46 which eliminates 4 in r3c6 we have

peterj · Joined: 26 Mar 2010 Posts: 974 Location: London, UK

I went chain hunting and this one does it in one...

George Woods · Joined: 28 Mar 2006 Posts: 304 Location: Dorset UK

for me it was 3 XY wings though whether it was neccesary it was certainly sufficient:-

First a 179 allowed a 479 to put a 1 in r7c5 and after a few more entries a 479 finished the job by putting a 2 in r7c4!

cgordon · Joined: 04 May 2007 Posts: 769 Location: ontario, canada

Two Type 6 URs (47) (78). 179 xy wing. BUG+1

Marty R. · Posted: Tue Apr 06, 2010 3:32 pm Post subject:

Obviously a different kind on VH. I played two W-Wings and got two eliminations from the same Hidden UR (78).

keith · Posted: Tue Apr 06, 2010 3:52 pm Post subject:

So far as I can see, four XY-wings are required: 1-79, 4-79, 67-8, 6-78.

(Recall, you should be able to solve it with only X, XY, and XYZ wings.)

Keith

peterj · Joined: 26 Mar 2010 Posts: 974 Location: London, UK

Keith, interesting comment - I am new to this site and was wondering what sort of level VH is meant to be.

There seems to be a strong bias in the setter to xy-wings - which are almost always necessary it seems. Avoiding them is an interesting challenge!

I cut my teeth on the mepham diabolicals which are harder (or used to be) and colouring is usually the best 'bang for buck' weapon in the armoury.

Enjoying dannys puzzles too..

Mogulmeister · Joined: 03 May 2007 Posts: 1151

I really do resemble that remark Peter.

Wendy W · Joined: 04 Feb 2008 Posts: 144

I dunno, guys -- I did it with only two xy-wings: 678 and then 179. Took me a while to find them, though!

RobertRattley · Joined: 24 Jun 2007 Posts: 118 Location: Australia

I concur with Keith. I've solved all Daily Sudoku puzzles, and advanced techniques beyond those 3 kinds of wings have never been needed (pleasurable though different techniques may be to other solvers).

Four xy wings! Most unusual.

I do note Wendy's comments, but I don't feel in the mood to revisit the puzzle. Yes, if you're right Wendy, it takes a while to find them! Even though basics seem to go so far.

This is a beautifully constructed puzzle. Congratulations to the designer.