The New Sudoku Players' Forum

[Bernard Stay]

P.S. By the way, you didn't need a swordfish for this one, the crux is a particularly nasty hidden triple of {4,8,9} in block three. Find this, eliminate a '3' in block 2 and Robert is, as they say, a sibling of one of those two infinitely generous members of the race who spawned you.

Thanks, K. I got the triple, but (unless I invoke the 'swordfish - which I'm not sure about) it still leaves me at:-

5**|***|***
4**|*7*|*56
9*8|4*5|***
--------------
21*|**3|*9*
**5|2*9|6**
*49|8**|*2*
--------------
**2|6*4|573
7*3|*2*|*64
**4|***|2*9

The next step?

Thanks.

[Karyobin]

Right, the order I did it is as follows:

1. There are 8's locked in a row in block 4. This means you can remove 8's as candidates from block 6 row 5.

2. There are 3's locked in a column in block 1, which means you can remove 3's as candidates in block 4.

3. Use the x-wing in cells r2c6, r2c7, r8c6 and r8c7 to remove some candidate 8's in columns 6 and 7.

4. There is now only one place for an 8 in block 6, which removes the 8 as a candidate from r1c9. The hidden triple in 4's, 8's and 9's is now more obvious in block 3. At this point you can also place a '5' in block 6, as there's only one place it can go.

5. There are 3's locked in a row in block 3, so you can remove candidate 3's from row 3, blocks 1 and 2.

6. Now, you have the naked pair {1,6} in column 5, exposing a '4' in r5c5 and subsequently a '5' in r4c5.

The rest is easy, complete row 4, complete block 4, continue ad nauseam.


Sorry silvercar, you must have a very masculine writing style. ;-)

[Enigma]

Only just looked at yesterday's superior... unless I'm missing something, I don't believe you need to touch triples or x-wings to solve it. Locked rows/columns and pairs did it for me. I may have taken a jump in logic somewhere that did involve triples, but I don't think I did.

Also, I see that following on from Saturday's Samurai when there was a cunning (or maybe blatantly obvious) pattern to the initial grid (and which I totally missed until someone POINTed it out to me), did anyone spot the theme evident in yesterday's Superior ?

[Bernard Stay]

Right, the order I did it is as follows:

1. There are 8's locked in a row in block 4. This means you can remove 8's as candidates from block 6 row 5. etc.

The rest is easy, complete row 4, complete block 4, continue ad nauseam.

Thanks K for going to all that trouble. (At least I did the Mephisto - which between you & me is really much more interesting a challenge than Su.)

[Karyobin]

Cryptic stuff? I try, but I never practice enough. I get bored of thinking in the required labyrinthine way, so invariably I give up and thrash my mobile at chess.

Small victories.

[PaulIQ164]

I'm a little stuck on this sudoku myself. I got this far:

Code: Select all

+-------+-------+-------+
| 5 . . | . . . | . . . |
| 4 . 1 | . 7 . | . 5 6 |
| 9 . 8 | 4 . 5 | . . . |
+-------+-------+-------+
| 2 1 . | . . 3 | . 9 . |
| . . 5 | 2 . 9 | 6 . . |
| . 4 9 | 8 . . | . 2 . |
+-------+-------+-------+
| . . 2 | 6 . 4 | 5 7 3 |
| 7 . 3 | . 2 . | . 6 4 |
| . . 4 | . . . | 2 . 9 |
+-------+-------+-------+

But what's puzzling me particularly is that I put the puzzle into Sudoku Susser, checked all the logical methods I understand Pappocom puzzles to employ (to whit, the first six on the list, up to and including Comprehensive Locked Set), and Susser only got exactly as far as I have. What's going on?

[Karyobin]

No idea matey. I just copied your code, dumped it straight into Angus's and continued à la the steps given above. Solved it again no problem: one x-wing, one hidden triple and off to bed. Metaphorically.

[PaulIQ164]

Strange. I guess Susser just doesn't do X-Wings. Anyhow, as long as the problem's with the program (and with me) and not the puzzle I guess there's no need to take it further in this forum. I think I'll just conveniently avoid Sunday Times puzzles from now on.

[Karyobin]

Well, I'm not - they're the hardest ones of the week!

[PaulIQ164]

I think they're just a bit too hard for me to enjoy doing them really. Presumably to solve one you have to clutter the page with quite a lot of untidy candidates and other inelegant sribblings? You can tell by my unnecessary use of pejorative modifiers that I'm not a fan of this sort of solving.

[Kanfield]

I agree with Karyobin that the superior is the hardest of the week. Every week I promise myself I will not log on to the forum and get help but I always give in. Then I kick myself for not seeing what on occasions is a straightforward step. Well I will just have to use more willpower next Sunday!