Logic Masters Deutschland e.V.

Double Dutch Sudoku Advent (16) - Even Sandwich vs. Hidden Skyscrapers

(Published on 16. December 2014, 12:00 by Eisbär)

Richard and I have created a fresh sudoku advent calendar in which we combine a well known variant with a relatively unknown variant every day. Combining variants leads to interesting and surprising new solving techniques.

Logically solvable
All puzzles can be solved completely logically although the logic is sometimes well hidden and is inherent to the combination of restrictions that the different types offer. For that reason we have written some solving hints for most of the puzzles, published in a very tiny font. If you want to read the hints, simply copy these in a text editor and enlarge the font size.

Even Sandwich
Place the digits from 1 to 9 in every row, column and 3x3-block. Clues outside the grid show all the digits that have even digits as neighbours on both sides in the corresponding row or column.

Hidden Skyscrapers
A cell contains (an) arrow(s) if and only if the number in that square correctly indicates the number of skyscrapers visible in that direction. Every digit represents a skyscraper of the given height. Higher skyscrapers block lower skyscrapers.


Solving hints

1 in R9C8; 1 in R7C2; 1 in R8C5; 1 in R2C4
Pair {59} in R46C5; R3579C5 all even
R2C5 = 7; R1C5 = 3
R13C4 both even; R1C6 must be odd since 3 and 7 both not sandwiched in R1
both 5 and 9 in C4 in block middle bottom.
Since 5 is sandwiched in C4: R9C4 = 9; R7C4 = 5; R68C4 both even
3 in R5C4; 7 in R4C4
Now look at R4: R4C7 = 2; R4C8 = 6; R4C69 = pair {48}

Solution code: Row 2, followed by Row 8

Last changed on -

Solved by Kwaka, NikolaZ, Statistica, fridgrer, SilBer, r45, lutzreimer, BFaw, Luigi, KlausRG, marcmees, matter, Florian82, RALehrer, mjaipal, pin7guin, Danielle, berni, Joe Average, tuace, Alex, cornuto, ... PRW, RobertBe, rcg, skypper, dm_litv, yusaku, sojaboon, zhergan, JonaS2010, Saskia, Matt, Julianl, Marian, bob, cdwg2000, keelyc27, EKBM, geronimo92, ParaNox, Krokant, misko, qw014052, vmirandaa
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Comments

on 8. December 2023, 00:25 by vmirandaa
Penpa+ link:

https://tinyurl.com/ykrb9hqj

on 17. December 2014, 13:24 by flaemmchen
Hat mir besonders gut gefallen :-))

on 16. December 2014, 19:57 by berni
Das war für mich genau der richtige Schwierigkeitsgrad. :-)

Difficulty:2
Rating:90 %
Solved:99 times
Observed:8 times
ID:00024N

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