The New Sudoku Players' Forum

[Bernard Stay]

(Correct Forum?)

Having had little or no trouble with tough or deadly Times killer puzzles until yesterday, I hardly got anywhere with yesterday's and haven't even managed a single firm entry in today's. Can anyone give me a hint how to get started?

Thanks.

[TKiel]

Can you post the puzzle?

Tracy

[Bernard Stay]

Can you post the puzzle?

Tracy

Tracy

Not easily, being a Killer with all those little dotted boxes. Today's is Killer No 147 - Deadly. Yesterday's Killer No. 146 - Deadly.

Thanks.

[jimbob]

Yesterday's puzzle (#146) can be found at www.timesonline.co.uk/. Today's (#147) will presumably be there on Monday.

I agree #146 was harder than they usually are. I solved it OK, I didn't keep a record of how I did it, but I think the interaction of the 23/3 cage in N58,the 16/2 cage in N78 and the 22/3 cage in N45 provided the first important moves.

I haven't tried #147 yet (or any in the supplement today).

[udosuk]

Posting killers in text shouldn't be that hard. As a guide, you could copy the following to Notepad:

Code: Select all

+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+
+---++---++---++---++---++---++---++---++---+
| * || * || * || * || * || * || * || * || * |
+---++---++---++---++---++---++---++---++---+


There, fixing the fences and adding the cage sums, it should take less than 5 mins. For example:

Code: Select all

Magic Killer by Jean-Christophe
21-------+23------------+17--+23------------+
| *    * || *    *    * || * || *    *    * |
|   +----++----+   +----+|   |+----+   +----+
|   |14-------+|   |+----+   |22--+|   |19--+
| * || *    * || * || *    * || * || * || * |
|   |+----+   |+---+|   +----+|   |+---+|   |
|   |20--+|   |14--+|   |18--+|   |+----+   |
| * || * || * || * || * || * || * || *    * |
|   ||   |+---+|   |+---+|   ||   |+----+   |
|   ||   |+----+   |15--+|   ||   +----+|   |
| * || * || *    * || * || * || *    * || * |
+---+|   |+--------+|   ||   |+--------++---+
+----+   |22-------+|   ||   +----+15-------+
| *    * || *    * || * || *    * || *    * |
+--------++----+   ||   |+--------+|   +----+
24--+18-------+|   ||   |18-------+|   |27--+
| * || *    * || * || * || *    * || * || * |
|   |+----+   ||   |+---+|   +----+|   ||   |
|   +----+|   ||   |15--+|   |16--+|   ||   |
| *    * || * || * || * || * || * || * || * |
|   +----+|   |+---+|   |+---+|   |+---+|   |
|   |21--+|   |+----+   |23--+|   +----+|   |
| * || * || * || *    * || * || *    * || * |
+---+|   |+---+|   +----+|   |+--------+|   |
+----+   +----+|   |+----+   +----++----+   |
| *    *    * || * || *    *    * || *    * |
+-------------++---++-------------++--------+


[jimbob]

Just completed #147, again it's more difficult than usual Times killers, but not too difficult.

After obvious starting options on 29/4, 7/3, 4/2 cages, I started off looking at interaction of N23 12/4 cage, N3 9/2 cage and N69 8/3 cage which leads to r7c9=5. From there innies/outies on r89 lead to r7c8=3.

Good luck from there.

[Bernard Stay]

Just completed #147, again it's more difficult than usual Times killers, but not too difficult.

After obvious starting options on 29/4, 7/3, 4/2 cages, I started off looking at interaction of N23 12/4 cage, N3 9/2 cage and N69 8/3 cage which leads to r7c9=5. From there innies/outies on r89 lead to r7c8=3.

Good luck from there.

I've obviously not been following the Killer postings, because I can't make head or tail of the above. What's an 'N'?

Never mind, thanks anyway. I've just done today's Sunday Times Superior No. 32 which will keep me reasonably happy for a while. Now for the Mephisto!

[jimbob]

Sorry, I'll try to explain.

N means nonet, another name for box. So N1 means the top left hand box, N2 means the top centre box, etc. Since cages can cross into more than one box we may need to refer to more than one box for any particular cage.

N23 12/4 cage - this means the cage covering 4 cells, sum 12 contained in nonets (boxes) 2 and 3, ie top centre and right.

The 9-sum cage in column 9 cannot be 1,8 or 4,5 since the 8-sum cage in the same column must contain a 1 and also contain either 4 or 5. Therefore the 9-sum cage must be 2,7 or 3,6. If it was 2,7, then r1c6 must be 2, since the 12-sum cage must be either 1,2,3,6 or 1,2,4,5. But since nonets 3 and 6 must add to 90, r1c6-r6c9=4, so r1c6 cannot be 2.
So the 9-sum cage must be 3,6. This leaves the 8-sum cage to be 5,1,2. Since the 7-sum cage in row 7 must already use 1,2,4 this places the 5 in r7c9.

Since all rows add to 45, the sum of r8 and r9 must be 90. By observing cages in the bottom 2 rows we find that r7c2+r7c8-r8c9=9. We know r8c9 is 1 or 2 (part of 5,1,2 8-sum cage). We also know that the 7-sum cage in row 7 uses 1,2,4. Therefore r7c2 and r7c8 must be 3,7 or 3,8 (depending on the value of r8c9). But c2 must already have a 3 in the N4 4/2 cage.Therefore the 3 must be in r7c8.

[Edited to include extra step omitted originally]

[CathyW]

Times Killer 147 was certainly more difficult than usual. I went wrong in the paper and recreated it using djape's Perfect Sudoku which rated it at Insane level. (Screen capture, paste image in Word and reprint to have another go). Solved on the second attempt thankfully, but delighted to have more challenging Killers in The Times.

Having the difficult Killer here and more variants in the Championship supplement made up for the somewhat easy "Superior" in today's ST.

(btw this thread should probably be in Variants forum as Pappocom don't do the Killer puzzles!)

[djape]

Cathy,

147 is rated IQ (low-end, close to BRAIN) by the new version of PS. It requires some cage splitting, which wasn't fully implemented in v0.4.

146 is rated THINKER.

[CathyW]

Thanks for that DJ - I always knew your puzzles were much more challenging than anything produced in The Times so far, though they seem to be getting there with no. 147. When will the new version of PS be available for download?