BrainDen.com - Brain Teasers

# plasmid

VIP

1742

22

1. ## Is this original riddle decent for a teenager?

Initial thoughts are that
2. ## Help needed trying to write a program to solve a puzzle

The first thing that jumps out at me is that when I do Einstein puzzles by hand I usually need to do many iterations of going through the rules and filling out as much as I can, and then going through the rules again to narrow things down further based on what I’ve eliminated so far. In this case there’s a single loop of For cr = 1 to cntRules that gets executed once, as if a human were to just go through all the rules once instead of iteratively. If you as a human are able to solve the puzzle by going over each of the rules once in the order that they're presented, then the program
3. ## Help needed trying to write a program to solve a puzzle

We'll have to see the algorithm and what it's doing in order to say much. Could you share it and walk through how it would handle an example Einstein puzzle that folks without the game could follow (say the one at https://web.stanford.edu/~laurik/fsmbook/examples/Einstein'sPuzzle.html)? If you solve the puzzle the old fashioned way and keep track of what you eliminate and why, is your algorithm able to recreate the path to the solution? If not, then what parts is it missing?
4. ## Groundhog in a Hole - Yet Again

Ah, I see. So in that spirit you could present your solution #2 this way (not particularly efficient, but crystal clear that it works)
5. ## Groundhog in a Hole - Yet Again

I'm afraid I might be missing something, because it seems like whenever you switch parity you end up losing all the ground you previously covered. Consider xp2008's solution... Similarly for EventHorizon's first solution You could argue that if you start off covering a finite area, then cover a slightly larger area, then cover a slightly larger area, etc. then you will eventually catch the groundhog because the groundhog must be at some finitely numbered hole which you will eventually reach. My counterargument to that is:
6. ## Stonenibblers

Only if they're imaginary stonenibblers.
7. ## I'm not a rebellious missionary

Just a reference to something commonly associated with it...
8. ## Once more with the Maiden

After more thought:
9. ## Once more with the Maiden

I'm pretty sure this isn't optimal, but it's a start.
10. ## Probability 101

I agree completely with EventHorizon, and will try to summarize in a way that addresses the OP and deconvolutes the paradox at its heart:
11. ## Probability 101

The part that I turned red in the quote bugs me a little bit.

It looks like that will indeed work. And I know I just said this about the previous solution, but now I really don't think there's a way to do it with any fewer breadcrumbs. As for ever finding a general solution to the breadcrumbing problem,

I would have to disagree with that since I just posted a solution with only one breadcrumb going from C to E. But I do agree that there probably isn't a better solution for the pentagon case than adding five new breadcrumbs.

That's the best solution so far, and matches the number of breadcrumbs I had even though it seems substantially different. I strongly suspect that there aren't any better solutions with fewer breadcrumbs, although I don't know of a way of proving it, let alone finding a general solution for determining the fewest number of breadcrumbs it would take to "teach" a dumb but hungry mouse to travel any arbitrary path. And I sort of doubt that anyone has figured it out since this sort of puzzle isn't a common thing. But I'll go ahead and share my perspective on the problem and the solution I reached.

That's correct. The mouse can take whatever path you want it to take, even if it's not straight lines from A to C to E to B to E, as long as it reaches the specified destinations in the specified order. And it took me more than a day or two, so I certainly wouldn't fault you if it takes more than that.

Sort of a hint... (But note the edit below the spoiler before you open the spoiler.) Edit: To clarify: the mouse doesn't need to travel along straight lines to each of the points. It can go along any curved, jagged, or whatever sort of two-dimensional path you want, which makes the problem more interesting. If that's enough clarification, then don't open the spoiler :3

CaptainEd has the best answer so far and asked to see my solution so I'll go ahead and PM it, but will leave this open in case anyone else drops in and wants to take a crack.

Putting coordinates into a spreadsheet and calculating distances sure is a good way of checking your work; now I wish I had thought of doing that! I believe I have a way of doing it with five breadcrumbs aside from the five vertices. Up to you if you'd like to look at it a little longer or if I should go ahead and convert my chicken scratch to an intelligible post when I get a chance.
20. ## A Living Riddle

Well, I blew it with the first guess...

I see what you're saying -- if we don't care whether the mouse goes from C to B or from C to D then that would work and you could let the mouse just flip a coin after it reaches C. The OP was phrased sort of ambiguously since I first talked about making the mouse take as many diagonals as possible (in which case that would be fine to do) and later said the specific letter sequence of ACBD (in which case that wouldn't). The only thing I'd say, though, is that if you drop a breadcrumb in region E, it seems like the mouse would go eat the breadcrumb there and then go to either B or D instead

Yep, this gets harder than it looks

... wut? ... Wat? The mouse always goes and eats the nearest bit of food to its current position. So like Captain Ed says, putting multiple pieces of food at one spot wouldn't be helpful. If the mouse starts at point A of the square, then the food at either B or D will be closer than C (even if there are multiple breadcrumbs at C), so the mouse will go to the closer food at either B or D. Nah, this mouse really is pretty dumb. It won't manage to learn, it'll still keep right on pursuing whatever bit of food is closest until it eats everything in sight.
24. ## A Living Riddle

I'll go with ...
25. ## Triangle probability

This gets tricky with rolls like (1, 1, 6) that look isosceles but don't actually form triangles. How would you handle such rolls? Would you omit rolls that don't form a triangle from analysis (equivalent to saying that if you get a roll that doesn't form a valid triangle then roll again), or count them as a failure to form an isosceles triangle? And would you consider a "straight line" throw like (3, 3, 6) to be a valid triangle albeit with zero area or nah?
×

• #### Activity

• Riddles
×
• Create New...