Speed Sudoku

Speed Sudoku - Play web sudoku puzzle games online for free!

Ready to play fast-paced sudoku races online? Create an account & start playing!

XYZ - Wings:

How to win at Speed Sudoku?

XYZ - Wings:

Postby strmckr on Sun May 10, 2009 4:30 am

this is a quote from scanraid.com whom has better write ups on move sets then i will ever be able to explain.

This is an extension of Y-Wing or (XY-Wing). John MacLeod defines one as "three cells that contain only 3 different numbers between them, but which fall outside the confines of one row/column/box, with one of the cells (the 'apex' or 'hinge') being able to see the other two; those other two having only one number in common; and the apex having all three numbers as candidates."

It follows therefore that one or other of the three cells must contain the common number; and hence any extraneous cell (there can only be two of them!) that "sees" all three cells of the Extended Trio cannot have that number as its true value.

It gets its name from the three numbers X, Y and Z that are required in the hinge. The outer cells in the formation will be XZ and YZ, Z being the common number.


Code: Select all
.   .    . |  .  .   . |  .  .  .
-z  xyz -z |  .  xz  . |  .  .  .
yz  .    . |  .  .   . |  .  .  .
-----------+-----------+----------
.    .   . |  .  .   . |  .  .  .
.   .    . |  .  .   . |  .  .  .
.   .    . |  .  .   . |  .  .  .
-----------+-----------+----------
.   .    . |  .  .   . |  .  .  .
.   .    . |  .  .   . |  .  .  .
.   .    . |  .  .   . |  .  .  .
Last edited by strmckr on Sun May 10, 2009 4:44 am, edited 2 times in total.
User avatar
Grand Guru strmckr
 
Posts: 188
Joined: Fri Apr 24, 2009 5:57 pm

Re: XYZ - Wings:

Postby strmckr on Sun May 10, 2009 4:31 am

Example: xyz wing:
Code: Select all
.---------------.------------.----------------.
| 4   1     5   | 7    39  2 | 8    369  36   |
| 29@  236-9  369 | 8    1   4 | 279  5    237  |
| 7   239@   8   | 5    39  6 | 1    239  4    |
:---------------+------------+----------------:
| 1   8     2   | 6    4   3 | 5    7    9    |
| 5   39@    39  | 1    8   7 | 26   4    26   |
| 6   4     7   | 2    5   9 | 3    8    1    |
:---------------+------------+----------------:
| 29  7     1   | 39   6   5 | 4    239  8    |
| 8   569   469 | 349  2   1 | 679  369  3567 |
| 3   2569  469 | 49   7   8 | 269  1    256  |
'---------------'------------'----------------'


3/2/9 in r2c1,r35c2 => r2c2<>9
User avatar
Grand Guru strmckr
 
Posts: 188
Joined: Fri Apr 24, 2009 5:57 pm


Return to Strategy

Who is online

Users browsing this forum: No registered users and 2 guests