## Expanded Uniqueness Type?

Advanced methods and approaches for solving Sudoku puzzles

### Expanded Uniqueness Type?

Do any solvers out there look for uniqueness patterns for more than U4, i.e. U6 or U8? I found a U6 in this puzzle:

Code: Select all
`5   7   6   | 3   8   1   | 9   24  24 8   19  12  | 4   6   29  | 3   7   5  3   49  24  | 7   29  5   |*18 *18  6  ------------+-------------+------------4   18  18  | 2   5   3   | 6   9   7  9   6   5   | 8   1   7   | 4   23  23 2   3   7   | 9   4   6   |*15 *15  8  ------------+-------------+------------7   5   48  | 6   39  489 | 2   348 1  6   2   3   | 1   7   48  |*58 *458 9  1   48  9   | 5   23  248 | 7   6   34 `

Obviously this is a simple Type 1, but for a U6 instead of a U4.

I also know that the puzzle solves with an XY-chain (r3c2-r3c5-r9c5-r9c9), and so the pattern isn't needed here, but it serves as an example none the less.

I haven't implemented Uniqueness Tests in my solver yet, but I'm wondering how common it is for solvers to look beyond U4.
Last edited by EnderGT on Tue Nov 30, 2010 2:01 am, edited 1 time in total.
EnderGT

Posts: 69
Joined: 19 February 2008

### Re: Expanded Uniqueness Type?

Dabeer wrote:Do any solvers out there look for uniqueness patterns for more than U4, i.e. U6 or U8? I found a U6 in this puzzle:

Code: Select all
`5   7   6   | 3   8   1   | 9   24  24 8   19  12  | 4   6   29  | 3   7   5  3   49  24  | 7   29  5   |*18 *18  6  ------------+-------------+------------4   18  18  | 2   5   3   | 6   9   7  9   6   5   | 8   1   7   | 4   23  23 2   3   7   | 9   4   6   |*15 *15  8  ------------+-------------+------------7   5   48  | 6   39  489 | 2   348 1  6   2   3   | 1   7   48  |*58 *458 9  1   48  9   | 5   23  248 | 7   6   34 `

Obviously this is a simple Type 1, but for a U6 instead of a U4.
I also know that the puzzle solves with an XY-chain (r3c2-r3c5-r9c5-r9c9), and so the pattern isn't needed here, but it serves as an example none the less.
I haven't implemented Uniqueness Tests in my solver yet, but I'm wondering how common it is for solvers to look beyond U4.

Edit: By the way, this is old user EnderGT, still waiting for a password reset to get access to the old screen name.

Wow..., nothing new that's MUG
Edit: it's actually a BUG-Lite (thanks ronk)=> r8c8=4
BTW, welcome back EnderGT...!

ttt
Last edited by ttt on Tue Nov 30, 2010 2:41 am, edited 2 times in total.
ttt

Posts: 185
Joined: 20 October 2006
Location: vietnam

### Re: Expanded Uniqueness Type?

ttt wrote:Wow..., nothing new that's MUG => r8c8=4