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Comment by calambrac | Hacker News Reader

I'm all for thinking outside the box, but the whole point of a puzzle is to set up a set of constraints and work your way from there. The solution to #1 seems to contradict that spirit - without spoiling it, it's true the description didn't say they couldn't do what they need to do, but it also didn't say they couldn't riot, kill all the guards, and just escape to avoid playing the game altogether...

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I fail to see how the solution to #1 contradicts the plain meaning of the constraints. I think it's an ingenious and surprising result.

I guess it depends on how you interpret 'lined up'. What if the room is circular, the table runs around the circumference, and you enter the room through a trapdoor in the center? Then your entry point to the list is effectively randomized and on any given trial the algorithm will work no better than chance.

Well, there are actually two unstated preconditions that need to hold for proposed strategy to work:

1) every prisoner uses the same entry (with the same reference frame in respect to boxes)

2) there are no changes in the arrangement of boxes between prisoner visits (this is extra requirement, as it includes wardens not doing any rearrangements in the meanwhile)

But otherwise, the strategy could be extended for arbitrary topologies - just state additional algorithm for defining starting point of labeling and then use a deterministic rule telling which box would be the next one.

For example, for circular arrangement - start at 12:00 and go clockwise.

Or, for arbitrary random arrangement - start at upper left box and then proceed in (axis-aligned) grid: leftmost->rightmost->down to next leftmost->repeat.

I believe the standard interpretation of 'lined up' is 'in a line', as in a 'straight curve', which disallows your otherwise ingenious foil.

True. But as soon as I thought of the circle, I said to myself 'ah, the idea that it's a straight line is exactly the sort of assumption that you gets you into trouble!' so I threw the whole solution out.

I figured a straight line would be equivalent to a random arrangement with each of the boxes being numbered, so I assumed the vagueness was designed to lead one into making a foolish assumption about their ordinal presentation. Maybe I'm paranoid :-)

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That's ridiculous. Proposing a nonsense solution certainly doesn't risk giving anything away. (You claim that there is a 100% likelihood the warden will cooperate and put the names in the boxes the prisoners request?)

If you think there's something wrong with the solution provided, why not just come out with it, and write "SPOILER WARNING" before it? I suspect you're misunderstanding something, though.

You're right, I misread it as "The prisoners get the Warden to label the boxes randomly", with the same implicit assumption as anigbrowl, that the prisoners don't have enough information beforehand to assign an order to the boxes.

The warden is not compelled to cooperate.

I disagree, this is a great puzzle and is pretty well specified.

I fully agree. The described solution is easily defeatable without violating the other conditions.

Defeatable? What on Earth does that mean? The goal of these puzzles is to find a solution, not to foil the given solution. "Lined up on a table" has a common-sense meaning. Everything else in this puzzle and the solution is purely based on the common-sense meaning of the words used.

Well, given my erroneous thinking about lines vs. curves (something you sometimes see exploited in other puzzles), when I say 'defeatable' I mean from the point of view of the warden, who would be seeking to minimize the prisoners' chances of success. You know, 'mwuhhahaha! I never said they were in a straight line' or indeed 'mwuhahaha, I never said we were in Euclidean space!'.

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