Battleships! - Sudoku
(Published on 28. March 2021, 06:13 by JeffWajes)
By Jeff Wajes
You are our navy's finest admiral. We have tracked the enemy fleet to this narrow harbor, and now we need you to pinpoint their locations so that we can sink them for good.
Happy hunting!
Rules
Normal Sudoku rules apply. Digits cannot repeat inside a cage. The small clue in the top left of a cage indicates the sum of the contained digits.
There are exactly five enemy ships. There are two ships that are 3 cells long, and one ship each of lengths 2, 4, and 5. See list below.
Cells in the given cages (green) are land. All other cells (blue) are sea. Ships can only occupy sea cells.
Ships cannot touch each other, not even diagonally.
Each ship acts like a cage with a sum of 15.
Ships are unambiguous, and the negative constraint applies. In other words, any line of 2, 3, 4, or 5 sea cells which sum to 15 MUST be a ship. Similarly, any line of sea cells which cannot be a ship CANNOT sum to 15. This will be important.
Solution code: Column 4
Comments
on 1. July 2021, 16:50 by Phistomefel
This was a very entertaining puzzle. Thanks a lot, JeffWajes!
on 9. June 2021, 22:12 by DiMono
Nicely done. Thanks for the fun puzzle. I've been toying with my own battleship/sudoku hybrid idea; I can only hope it turns out as nicely as this one.
on 24. May 2021, 22:50 by Zombie Hunter
Missed an early bit of logic that caused me grief. Logic is your friend in this excellent puzzle. Nice construction. Make more.
on 2. May 2021, 05:08 by cristophermoore
Fantastic puzzle! Multiple kinds of reasoning, the negative constraint applying in a bunch of places, a quick break-in but many more insights to be had along the way. Thank you so much!
on 2. May 2021, 01:07 by cristophermoore
Fantastic puzzle! Multiple kinds of reasoning, the negative constraint applying in a bunch of places, a quick break-in but many more insights to be had along the way. Thank you so much!
on 28. March 2021, 22:03 by fuxia
Fantastic puzzle! Clever use of the negative constraint, I enjoyed this a lot. Thank you.
on 28. March 2021, 19:25 by Sktx
Very nice idea ! It stays tricky from start to end, and the ruleset is quite clean. I wish I could win my battleships! games with that kind of logical path...
on 28. March 2021, 10:54 by PixelPlucker
I really enjoyed this! It has a very compelling hook and an enjoyable solution path with some fun challenges.
