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Category: Community
Forum: Chat Room
Thread: Weekend Puzzles |
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Thread Status: Active Total posts in this thread: 269
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alanb1951
Veteran Cruncher Joined: Jan 20, 2006 Post Count: 858 Status: Offline Project Badges: 
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Adri,
Thanks for the supplementary information... I presume that if you'd found 26 you would have discarded one rather than doing 13x2 :-) [No need to answer that!] Cheers - Al. |
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Sgt.Joe
Ace Cruncher USA Joined: Jul 4, 2006 Post Count: 7545 Status: Offline Project Badges: 
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An interesting puzzle and an interesting explanation. The only other possibilities for countries with 5 letters in their names (in English) are two deprecated ones which have changed their names from what they used to be to different names now. One would be Myanmar which used to be called Burma. and the other is North and South Korea which when it was one country was called Korea. On the other hand Benin used to be called Dahomey.
----------------------------------------Al's explanation that decimals could denote geographic location was the key for me, although his suggestion to "think bigger" when I was thinking "Q" was Quito, Ecuador did not make sense until it occurred to me he meant countries, not cities. Cheers
Sgt. Joe
----------------------------------------*Minnesota Crunchers* [Edit 1 times, last edit by Sgt.Joe at Dec 20, 2023 3:50:11 PM] |
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OliviaZ6
Cruncher Joined: Jan 9, 2024 Post Count: 1 Status: Offline |
Thanks for the information!
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adriverhoef
Master Cruncher The Netherlands Joined: Apr 3, 2009 Post Count: 2069 Status: Offline Project Badges: 
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Hello and welcome to Killer Sudoku!
 The rules for regular sudoku apply and there is one simple additional rule: the sum of the cells in an enclosed cage must equal the total given for the cage. Each digit in the cage must be unique. A cage is surrounded by separate dotted lines with a total in the upper left corner, e.g.: 3┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄╮This example cage with 2 cells (and with given total 3) can only contain the digits 1 and 2. Sudoku in short: Each 3×3 subgrid (with 9 cells) — surrounded by bold lines (so there are 9 subgrids) — can only contain the digits 1 to 9 and each digit must be unique. Each line and each column with cells can only contain the digits 1 to 9 and each digit must be unique. KILLER SODOKU(I've added some arrows at the borders, two arrows at each border, to denote the bold lines inside the grid.) Good luck! Adri |
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alanb1951
Veteran Cruncher Joined: Jan 20, 2006 Post Count: 858 Status: Offline Project Badges:
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Adri,
Thanks for this -- it made a nice break after fighting the APIs to get statistics and track the status of the various post-validation daemons over the last week or so :-) It took me a while to solve because I kept forgetting that you'd got some 3-cell "cages" that went round corners :-) but I got there in the end... Once again, thanks! Cheers - Al. |
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adriverhoef
Master Cruncher The Netherlands Joined: Apr 3, 2009 Post Count: 2069 Status: Offline Project Badges:
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If you tried to solve the (Killer Sudoku) puzzle, thank you for your participation! Thank you, Al!
I've made a small change to the grid lines, so that the lines aren't interrupted anymore, anywhere. What follows is, I'm afraid, already the solution. So close your eyes if you don't want to see it … yet.  SOLUTION
Hope you enjoyed it a bit. Cheers, Adri |
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alanb1951
Veteran Cruncher Joined: Jan 20, 2006 Post Count: 858 Status: Offline Project Badges:
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Thanks - that confirms I got it right, rather than having found an alternate solution that met the constraints :-)
I'm intrigued as to how you verified that it only needed a couple of given values (the two 8s) to be sure it was solvable using the cage data... Cheers - Al. |
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adriverhoef
Master Cruncher The Netherlands Joined: Apr 3, 2009 Post Count: 2069 Status: Offline Project Badges:
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Al,
Good question! As I'm understanding you, you want to know why I needed the two 8s to solve the puzzle. Let's suppose we start the puzzle all over again, now beginning without the two 8s. Then, at some point you arrive at a point where there are two ways to solve the puzzle with a 1 and an 8: ┏━━━━━━━━━┯━━━━━━━━━┯━━━━━━━━━┳━━━━━━━━━┯━━━━━━━━━┯━━━━━━━━━┳━━━━━━━━━┯━━━━━━━━━┯━━━━━━━━━┓ So, if you'll agree with me, to continue, we need to add a 1 or an 8 here to remove the 'ambiguity'. It should be possible to solve the remainder of the puzzle without the need of the second 8. Furthermore, as you may have noticed, the placement of the 8s in the diagram is relative to each other mirrored along an imaginary diagonal axis running from bottom left to top right. Hope this helps answering your question.  Adri |
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alanb1951
Veteran Cruncher Joined: Jan 20, 2006 Post Count: 858 Status: Offline Project Badges:
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Adri,
Thanks for the reply; actually I was also thinking about the care that might need to go into how to decide how to arrange the cages, as with just the two given 8s several of the cages had to be able to be used to determine cell values quickly (such as the top left cell in this puzzle!) I suspect there are puzzle-constructor guidelines (rules?) that explain how to build puzzles at various difficulty levels, but I'm not privy to them -- I find it fascinating anyway :-) Cheers - Al. |
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adriverhoef
Master Cruncher The Netherlands Joined: Apr 3, 2009 Post Count: 2069 Status: Offline Project Badges:
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Al,
If you're interested, you may find a document on creating and grading several types of sudokus here (PDF). I can't find where I found the link, so it's here in my post. Adri |
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