Cake by the Lake
(Published on 20. July 2024, 00:00 by marty_sears)
Happy birthday to Lake, a fantastic setter and top bloke, who I am actually gonna meet in person today for the first time :) This puzzle is also in response to a prompt from gdc to set something with shaded cells that all act as some kind of modifier.
Rules:
- Normal sudoku rules apply.
- Colour some cells green (land) and some cells blue (lake). All cells of the same colour must be orthogonally connected. A 2x2 area may not be all land, but it might be all lake.
- LAKE: Lake cells must not touch the edge of the grid. The value of a lake cell equals its row number plus its column number, regardless of what digit appears in that cell. Eg: If r4c2 is lake then its value is 6.
- CAKES: The value of a cake cell indicates exactly how many cakes have that value.
- SAME DIFFERENCE: Adjacent values on a turquoise line always have the same difference. This difference must be determined for each line.
Click here to play on the CTC app
Please leave a comment if you enjoy :)
Solution code: row 5 from left to right
Comments
on 28. May 2025, 16:19 by Clementi
Another very nice, and unique, puzzle. Thank you.
A question about rules descriptions: for this one you specify the value of lake cells, but there is no definition of the value for land cells.
I figured that since there was no definition, the value of land cells must be their digit.
Is this a general default rule for sudokus?
Marty: it is yes :)
on 14. November 2024, 04:19 by jakestilesowen
I really like this puzzle and its different stages. Great setting!
on 9. September 2024, 13:40 by QuiltyAsCharged
Same difference lines
Shaded water and land
Work together so well
This puzzle is grand!
For Lake's birthday
A slice we will hoist
Of Cake by the Lake
So incredibly moist
on 14. August 2024, 22:51 by ChinStrap
Lovely! Now I want cake...
on 20. July 2024, 22:28 by ViKingPrime
The level of care and detail you put into your birthday puzzles is nothing short of remarkable. Phenomenal.
on 20. July 2024, 15:37 by Franjo
An extraordinary birthday present this is! Thank you so much for sharing this with us and: Happy Birthday, Lake!
on 20. July 2024, 15:25 by wuc
Awesome as always. I missread the rule that the border is all land... then its more complex :-). Rereading the rules made a lot suddently clear and 3 star is ok to me. What a joy solving thx once more.
on 20. July 2024, 07:46 by gdc
Very nice submission for the prompt. Liked the choice for shading rule and the modifiers. Also really cool interactions with the same difference lines.
on 20. July 2024, 03:02 by juggler
Beautiful logic in this one, as always! Really enjoyed that :)
on 20. July 2024, 02:23 by vitaminz
Quite a bit easier for me than the rating but might just be hitting my strong suits. Probably my favorite puzzle this month! Lots of deductions I wasn’t expecting when reading the rules.
on 20. July 2024, 01:58 by sorryimLate
Wow, that was super fun, fresh and clever! But definitely no more than 2* in my opinion. In mid-solve I thought I had broken it, but then noticed that I hadn't finished reading the sentence in the rules about 2x2. I had just assumed it's the normal yin yang.
on 20. July 2024, 01:16 by fractalminding
Perhaps you wanted to say that a 2x2 area can be completely land, but it cannot be completely water. Otherwise, I don't understand... After all, according to the rules, water can be in a very limited area of the grid. It must be an interesting sudoku. But I can't understand the rules yet...
Marty: No, a 2x2 may not be completely land. But it might be completely water. I'm not sure what you mean about water being in a very limited area of the grid? (to clarify, the value of a water cell does not necessarily equal the digit in the cell. So there might be a 7 in r1c1, but it would have a value of 2 rather than 7, for the purposes of the line its on.) Hope this helps?
