SudoCue Users

I guess I truly don't understand the technique. I had assumed that all puzzles requiring uniqueness do have more than one solution and that you used uniqueness to eliminate all but one of those. You're right, zoltag. You don't quite understand what Sudoku authors mean by the "uniqueness techni...

r6c1 must be 6 since uniqueness made r6c8 a 1. The puzzle is trivial, with one solution, at that point. I'm not sure how to say this. You're wrong, zoltag. The "uniqueness" technique can only be used if the puzzle has a unique solution. This puzzle has five solutions, so simple logic tell...

I'm still puzzled, this is not a false positive. Is it? Yes, you obtained a "false positive" when you tried to optimize the puzzle with "uniqueness" turned on. The puzzle you posted has at least five "solutions", as follows. Case 1A -- assume "uniqueness" at ...

Is Someone_Somewhere still somewhere out there? I last heard from Andrei about a week ago. He's on another software installation assignment in the UK (Lytham, wherever that is) which is no doubt keeping him very busy. I'll poke at the puzzle you posted for a little bit, but I can't make any promise...

Correct me if I am wrong, but aren't the official solution and David's producing a non unique situation at (2, 7-8) and (5, 7-8)? Good question, gerund. In the final solution, the pair {8, 4} appears in row 2, c7&8, and the pair {4, 8} appears in row 5, same columns. The thing is, the pair {8, ...

It also moved the "vote for this site" link a little higher up the screen, making it easier for me to find it. dcb

After making all the "obvious" moves (including the avoidance of a non-unique rectangle at r5&9, c2&3) I reached this position. 1 23459 2349 7 249 8 356 369 59 59 23579 239 2369 269 12369 8 4 1579 8 3479 6 349 5 139 13 1379 2 456 345 34 1 8 276 9 276 457 2 459 18* 569 679 679 1456 ...

I thought today's "nightmare" was tougher than most. 1..7..... ......84. 8.6.5...2 ...18.9.. 2.......3 ..7.34... 3...1.7.8 .65...... .....5..6 After avoiding a non-unique rectangle, I found a non-unique hexagon growing out of the same configuration. After dealing with that I found 5 double...

David, have you been solving the same puzzle? Yes, I was working the same puzzle. But I made a lucky(?) mistake, so my "solution" wasn't really valid. At the point you illustrated I started chasing the chain of "5"s and "7"s, and I must have miscolored a link somewhere...

Hi, Ruud!

I'm not sure if this is the "easy way" or not, but I noticed a naked triplet in column 1, which made the rest of the puzzle relatively straightforward. Some coloring on the "5"s and "7"s finished it off. dcb

You're writing a sudoku history? No, I'm not trying to write a history of sudoku. I'm just curious about words, and how old ones come to be associated with new concepts. I first learned about the "swordfish" sometime last summer ... late July or early August, I think. Anyway, the rubylips...

Any x-wing/seafood can be finned, and the fin allows sashimi variations where x-wing vertexes and entire swordfish/jellyfish rows can be missing. ... Yes, I've read some of those discussions already. Thanks for the link. Here's a question for you -- who turned the "swordfish" into "s...

Keith wrote:If the link is in the same site, stay in the same window.

If the link is in a different site, open in a new window.

I concur. This works best for me, too. dcb

Hi, Keith! From the position you posted two "doble-implication chains" will crack it wide open. The first is alpha star at r2c3: r2c3 = 8 ==> r2c8 = 1 r2c3 <> 8 ==> r8c3 = 8 ==> r9c5 = 8 ==> r7c8 = 8 ==> r2c8 = 1 Interestingly, this permits the same conclusion as your "unique x-wing.&...

The 27 March, 2006 "Nightmare" contains an instructive instance of the "template" elimination. After making a few fairly obvious moves I arrived at this position. 489 7 12589 1589 6 1289+ 459 249 3 469 12469 1259 3 1257 1279 8 24679 256 3 269 2589- 5789 2578 4 5679 1 256 1 34 7 2...