Battleships Logic Puzzle

Posted by QuadrupleA 10/25/2024

Battleships Logic Puzzle(lukerissacher.com)

254 points | 87 commentspage 2

waterhouse 10/25/2024|

I think "doesn't engage the language center of my brain" is more accurate (and less pejorative) than "mindless". It certainly engages spatial reasoning and some logic.

ndarray 10/25/2024||

Given the rules, it would be a better experience if squares only have two states: ship block or empty. There is no point to letting the user draw water. The feature probably exists with the intent of letting users mark squares that can't possibly be ships, but why wouldn't the game do that step by itself based on the blocks placed? That would make the game a lot less tedious.

joemi 10/25/2024|

It's indeed the way it is so that you can indicate a square that must be water. What you propose sounds like a solver to me, and I much prefer solving it myself.

snewman 10/26/2024|||

Note that very often, the solution process for a more difficult puzzle involves going through nontrivial logic to prove that a particular square must be water. It's important to be able to record non-obvious "must be water" squares.

ndarray 10/27/2024|||

If you do it as a purely visual representation of the game state, it won't be a solver, will it? Just all blocks surrounding ships + blocks in rows/cols with a 0.

dahart 10/27/2024||

Kinda addictive. I lost a few hours to this today. I hope you’re happy. ;) After getting pretty quick at the 15x15, it has minesweeper vibes. Works great on iPad, and the implementation is nice. Thank you for sharing.

uses 10/25/2024||

I've spent quite a few hours on this thing when I've needed something non-linguistic for my brain to engage in. If it was World of Warcraft, I'd probably be a level 30 rogue.

t00ny 10/25/2024||

Nice puzzle, reminds me of Zachtronics' Dungeons & Diagrams.

zeugmata9 10/25/2024||

Nice! In line with other apps like this (e.g. LinkedIn's queens), I think the grid should be marked complete once you have all the boats, without needing to mark all the water.

QuadrupleA 10/25/2024|

That might be good. One shortcut I did add, you can click the numbers to auto-fill water once a row is complete.

justinpombrio 10/25/2024||

This is one of the puzzles at BrainBashers:

https://www.brainbashers.com/battleships.asp

gnramires 10/25/2024||

An undo button would be nice :) (for when I need to backtrack)

QuadrupleA 10/25/2024|

If you turn on hardmode there's a "Save Checkpoint" button. But not easy mode at the moment (I wanted to keep the UI clean).

Gunax 10/26/2024||

This is advice to the creator:

I think there are unstated rules. Some are implied by the hints (eg 'you can fill water around a ship') but it's not clear to me at first why that hint works. It looks like ships can never share an edge, just based on the puzzles so far.

I am enjoying the game. Thanks for introducing me to something new.

QuadrupleA 11/1/2024||

Thread's pretty old now, but for posterity: there's now an automatic error dot if two ships are touching diagonally: https://lukerissacher.com/battleships

dahart 10/27/2024||

“Ships can’t touch, not even diagonally.” Doesn’t that imply ships can never share an edge, and that you can fill water around a ship?

Gunax 10/27/2024||

Yes! That's perfect now.

eapriv 10/25/2024|

There’s a bug: if a puzzle has multiple solutions, only one of them is considered “correct”.

QuadrupleA 10/25/2024|

Author here - check that the revealed ships in your puzzle are keeping their particular shape. E.g. a revealed-at-start "D" shape ship-end can't be the middle of a ship, or an "O" submarine, or face a different way that it's initially facing. 99.9% of the time people report this, it's a confusion about that aspect (if you can think of a way I can make it clearer definitely let me know!).

hibikir 10/25/2024|||

The simplest way would be to also pre-fill forced empty spaces. It 'solves' part of the puzzle for the player, but hopefully that wasn't a key part of the fun. You go as far as to explain all of those bits at the bottom anyway.

This kind of thing is done to great effect in "Good Sudoku", which gives players a lot of automated tools for the simplest things, as to lead players to handling the more fun, more complicated parts of the hard puzzles.

QuadrupleA 10/25/2024|||

Here's an experimental implementation, reveals the water cells around any revealed boats:

https://lukerissacher.com/battleships?revealwater=1

Not sure I like it, kinda makes the starting puzzle noisy/crowded.

QuadrupleA 10/25/2024|||

That would be a cool direction to explore.

rtkwe 10/25/2024||

Putting a blank space in front of or behind as appropriate for the starting revealed square(s) would make sure people don't keep having the problem.

andrewla 10/25/2024||||

I think the easiest way to make it clearer is to highlight it in red as a mistake if done incorrectly, as you do with the counts on the row ends. If you try to place a ship token close to another one then you should also highlight it in red.

QuadrupleA 11/1/2024||||

Think I found a good solution to this - there's now an immediate error message / red line when connecting incorrectly to a starting ship square: https://lukerissacher.com/battleships

pkasting 10/26/2024||||

First puzzle I got had four equally good solutions, none of which violated any of those.

acheron 10/25/2024|||

Yeah took me a bit to catch how the starting spaces worked. Not sure how to clarify that other than just writing it out in the instructions below.

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