Calcudoku puzzle forum
https://www.calcudoku.org/forum/

Not the End Of Year Puzzle :)
https://www.calcudoku.org/forum/viewtopic.php?f=5&t=518
Page 2 of 2

Author:  jaek  [ Thu Jan 09, 2014 7:57 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

clm wrote:
pnm wrote:
clm wrote:
Would it be possible to generate a 4x4 subtraction only without individual cells (solution unique, of course)?.


I think so :-)

...


Thanks [thumbup], undoubtedly very interesting (yes, solution unique), this type of puzzle requires a little more "thinking", at least to apply the parity rule, i.e., ...

I agree this was an interesting puzzle. And furthermore, not that difficult. That may largely be due to it being a 4x4, but those 7x7 subtraction-only puzzles are often the most difficult of the week for me, so I was prepared for more of a challenge.

One thing I did notice is that several cages were unnecessary to determine the solution. I started with 4b4c, then 3a3b4a, and then 1b1c2b. After that the other cells fell into place by process of elimination. I believe clm comments on this phenomenon on occasion, but it really stood out for me in this case.

Thanks to you clm for suggesting and to you pnm creating this start-of-the-year puzzle. :-)

Author:  nicow  [ Mon Jan 27, 2014 12:24 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

I love the new type of puzzle with unidentified numbers.

I made this one, and I'm not sure if the solution is unique.

Image
How can I get the picture here??
Edit: Thanks!

Author:  pnm  [ Mon Jan 27, 2014 12:36 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

nicow wrote:
How can I get the picture here??


Put the link in between a [ img ] and [ /img ] tag
(but without the spaces I put in)

(click on the "Img" button above the text edit area to insert a pair of these tags,
or simply type them)

Author:  clm  [ Mon Jan 27, 2014 8:18 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

nicow wrote:
I love the new type of puzzle with unidentified numbers.

I made this one, and I'm not sure if the solution is unique. ...


Very interesting [thumbup]. The solution I find I think is unique considering for the analysis "all" possible combinations for "6x" (positive and/or negative numbers, integers, of course, not fractional numbers) plus the 0.

Author:  kozibrada  [ Wed Jan 29, 2014 12:52 am ]
Post subject:  Re: Not the End Of Year Puzzle :)

nicow, clm: I have found "unidentified" numbers but also 5 solutions. Maybe I have made mistake in "3–" cage.
I send you PM with "my" possible solutions…

Author:  clm  [ Wed Jan 29, 2014 1:31 am ]
Post subject:  Re: Not the End Of Year Puzzle :)

kozibrada wrote:
nicow, clm: I have found "unidentified" numbers but also 5 solutions. Maybe I have made mistake in "3–" cage.
I send you PM with "my" possible solutions…


No mistakes in "3-", you are right, those 5 solutions are valid, I think I sent too fast my comments (I found the same set of numbers than you but I did not consider the possible swappings, thinking more in different sets of numbers), sure nicow will agree, this type of swappings occur frequently when designning these puzzles, anyway the puzzle is beautiful.

Author:  kozibrada  [ Wed Jan 29, 2014 1:58 am ]
Post subject:  Re: Not the End Of Year Puzzle :)

clm wrote:
No mistakes in "3-", you are right, those 5 solutions are valid, I think I sent too fast my comments (I found the same set of numbers than you but I did not consider the possible swappings, thinking more in different sets of numbers), sure nicow will agree, this type of swappings occur frequently when designning these puzzles, anyway the puzzle is beautiful.

OK, solutions was found, it’s major. [smile]
Yes, definitely, this type of puzzles is interesting and can be much tougher than 9×9 difficult (e.g.) puzzles…

Author:  nicow  [ Wed Jan 29, 2014 2:58 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

Thank you, kozibrada and clm!
I have made several puzzles of this kind now, and they indeed are very hard to be solved by hand.
And it is clear, my solver has to be developed further.

Author:  pnm  [ Tue Feb 18, 2014 5:51 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

nicow wrote:
I love the new type of puzzle with unidentified numbers.

More puzzles like that are described on
this page (where they call them "okidoku")

(instead of the correct name "Calcudoku with unidentified numbers" :-) )

Author:  clm  [ Tue Feb 18, 2014 11:17 pm ]
Post subject:  Re: Not the End Of Year Puzzle :)

pnm wrote:
nicow wrote:
I love the new type of puzzle with unidentified numbers.

More puzzles like that are described on
this page (where they call them "okidoku")

(instead of the correct name "Calcudoku with unidentified numbers" :-) )


Yes, this OkiDoKu looks in fact like a Calcudoku (all numbers must be different and the same pool of numbers is used for rows and columns) with two additional conditions: the freedom, the numbers are free for not being necessarily consecutive, if integers, so negative numbers are possible as well as the positive ones and the 0 (the other "advisable" condition: to be rational, I think). The consequence of that freedom is that several cages must necessarily be left "blank" (not sure about this, perhaps the no-op is possible too) while keeping the unicity of the solution (we have talked in our Forum about the "essential info in a puzzle", anyway).

I believe you can implement this, easily?, and publish one of these, as you do with the Sudoku (this time assigning points [smile]).

Page 2 of 2 All times are UTC + 1 hour [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/