Logic Masters Deutschland e.V.

The Pivot Point

(Published on 7. July 2022, 14:00 by Big Tiger)

F-Puzzles

Standard Sudoku Rules apply to the final numerical layout. Digits may not repeat along the two long diagonals.

Digits in cages must sum to the total in the top left corner of each cage.

The precise middle date of any non-leap year is July 2, with 182 days before it, and 182 days after it. Therefore 7/2 is the "pivot point". And so ...

Numbers outside the grid indicate that the digit "7" in that row or column touches exactly one "2". Moving from the 7 to the 2 indicates the direction of a line that continues on to the edge of the grid. The digits in that line (not counting the 7 and the 2) will sum to the number outside the grid. Digits may repeat where the rules of Sudoku allow.

When reaching the 7, the direction will always pivot to any other direction in order to move to the 2. It will never proceed straight through from the outside number to the other border of the grid. (Note the red "4" in the sample is incorrect because the path of travel does not pivot from the 7 to the 2.)

Only 7's that touch precisely one 2 are indicated by numbers outside the grid.

Per Skorp's request:

Solution code: Row 3, then Row 4

Last changed on on 8. July 2022, 01:03

Solved by efnenu, kikanya, bernhard, marcmees, bergelfe, purpl, cdwg2000, Uhu, OGRussHood, ildiko, SudokuExplorer
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Comments

on 8. February 2023, 21:45 by Big Tiger
Here's my short (but long delayed) response to Purpl's question: Why is this only two stars when it seems much harder? It includes a helpful pointer for starting the puzzle quite easily, so if you want to solve from scratch, don't watch!

https://youtu.be/P9lIxO19C_w

Last changed on 12. August 2022, 01:39

on 8. August 2022, 20:40 by purpl
I loved this puzzle once I understood the rules, but it took a few minutes. I don't think this is 2* due to the unfamiliarity of the ruleset.

I streamed my solve of the puzzle on YouTube, here is a link to the VOD with timestamp so perhaps some solvers would prefer hearing the rules outloud and seeing a few examples played out on the board: https://youtu.be/i0SsGvmxFvY?t=1987

*** Thank you, that was fun to watch! I'll see if I can pop up a response video on why I chose 2 stars instead of 3...

on 8. July 2022, 01:03 by Big Tiger
Added another sample graphic.

on 8. July 2022, 00:58 by kikanya
Here's a CTC link for anyone that prefers it over f-puzzles (as I do):

https://tinyurl.com/y57myy5k

on 8. July 2022, 00:51 by kikanya
@SKORP17
Nach erneutem lesen: Ja, ist missverständlich formuliert. Die Linien beginnen erst bei der 7 und verlaufen ab da, wie beschrieben.

Last changed on 8. July 2022, 00:47

on 8. July 2022, 00:47 by kikanya
The first time I looked at this I didn't know where to start, but when I came back after a while, the break-in revealed itself to me and opened up a beautiful puzzle. Very interesting ruleset and great setting, and most importantly, very fun to solve!

Perhaps this is closer to 3* than to 2* difficulty but I'm not too sure.

Note: I don't think the pivoting rule is necessary for the solve, at least I don't recall using it to deduce any line directions. And after having learned of this puzzles secrets, the last sentence is kinda funny to me. :)

Last changed on 8. July 2022, 00:48

on 8. July 2022, 00:41 by SKORP17
Danke, aber klar ist mir das nicht. Beginnen die Linien denn bei der 7 und führen durch die 2 bis zu Ende des Grid.
Verwirrend ist diese Regel
"When reaching the 7...." Das heisst doch, dass die Linie auch vor der 7 beginnen kann, aber wo ?

Diese Regel besagt doch, dass die Linie neben der Outside-Nummer beginnt, bis zur 7 führt und dann die Richtung ändert, durch die 2 bis zum Ende des Grid, aber das ist im Beispiel nicht der Fall.

on 8. July 2022, 00:30 by kikanya
@SKORP17
Jede 7 die zu einer der Zahlen außerhalb des Rasters gehört hat genau eine 2 in seiner direkten Umgebung. Die linien verlaufen so, dass diese beiden Zellen durchlaufen werden.
In dem Beispielbild sieht man, dass die 7 und die 2 diagonal zueinander stehen. Deswegen verläuft die Linie (markiert mit grünen Zellen) diagonal. Dabei beginnt sie bei der 7 und entwickelt sich über die 2 hinweg bis an den Rand des Rasters.
Hoffe das hilft dir weiter! :)

on 7. July 2022, 22:52 by SKORP17
ich verstehe nicht, wie die Linien verlaufen müssen, ein Beispiel wäre hilfreich

on 7. July 2022, 15:13 by efnenu
Very charming break-in and a smooth solving path, thank you!

on 7. July 2022, 14:00 by Big Tiger
Set to 2 stars

Difficulty:2
Rating:N/A
Solved:11 times
Observed:7 times
ID:000AF7

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