## Search found 160 matches

Tue Sep 26, 2017 10:54 pm UTC
Forum: Logic Puzzles
Topic: Could there still be new hat puzzles?
Replies: 12
Views: 10034

### Re: Could there still be new hat puzzles?

I'm just starting out the cheap way: generating different strategies and running stochastic simulations.

No need to be stochastic (with deterministic strategies, anyway). There are only 128 different ways to place the hats, faster and more accurate to just test each of them once.
Wed Sep 20, 2017 2:41 pm UTC
Forum: Logic Puzzles
Topic: Could there still be new hat puzzles?
Replies: 12
Views: 10034

### Re: Could there still be new hat puzzles?

Simple strategy: Each player should guess the hat color that she sees the most of. In a tie, she picks black. This succeeds in all cases except when there are 4 white hats and 3 black hats, in which case everybody guesses wrong. In a 4/3 split the other way, everybody guesses black, for 4 correct g...
Fri Jul 29, 2016 6:24 pm UTC
Forum: Logic Puzzles
Topic: Move one stick
Replies: 5
Views: 3546

### Re: Move one stick

You get at least one more if you allow bitwise operations: 6 | 4 ≠ 4 I don't know what that means. A Bitwise OR is an operator in programming, usually written as "|" in languages that have it. It essentially means: Write both values in base 2, then replace every 0 in one number with the c...
Fri Jul 29, 2016 4:19 pm UTC
Forum: Logic Puzzles
Topic: Move one stick
Replies: 5
Views: 3546

### Re: Move one stick

Spoiler:
You get at least one more if you allow bitwise operations:
6 | 4 ≠ 4
Tue Dec 15, 2015 4:28 pm UTC
Forum: Logic Puzzles
Topic: Computing a function without knowing the arguments
Replies: 6
Views: 3192

### Re: Computing a function without knowing the arguments

Seems like your hint makes it trivial? Build a machine that takes input and computes the function. Each person inputs their own half of the input. The machine computes the function and outputs the result. No communication between sentient beings has occurred. Which is clearly not what you had in min...
Tue Apr 14, 2015 10:12 pm UTC
Forum: Logic Puzzles
Topic: Cheryl's Birthday
Replies: 29
Views: 6499

### Re: Cheryl's Birthday

Easier than the versions of this with knowing the product and the sum of tuples of numbers. Albert knows that Bernard was told a day that exists in multiple months. So he must have been given a month that contains only duplicated days. May is out because 19 is unique, and June is out because 18 is u...
Thu Feb 05, 2015 8:29 pm UTC
Forum: Logic Puzzles
Topic: Simple puzzle from an app
Replies: 4
Views: 2209

### Re: Simple puzzle from an app

Spoiler:
All 2x2 subgrids add up to 15. Putting 2 in the center preserves that.
Sun Feb 01, 2015 6:57 pm UTC
Forum: Logic Puzzles
Topic: Six statements. How many are true?
Replies: 20
Views: 7292

### Re: Six statements. How many are true?

This is fairly simple if you disallow statements from being reducible to "this statement is false", a statement that can be considered neither false nor true. Assuming that, A forces B to be true, regardless of what B says. If B were false, A would be asserting that it's false, which w...
Sat Jan 24, 2015 2:31 pm UTC
Forum: Logic Puzzles
Topic: Gambling with the magical genie
Replies: 27
Views: 7276

### Re: Gambling with the magical genie

To me, that read like a nice, intuitive discussion of ways to look at the Rule, interspersed with unsupported hostility toward it. It's an unusual combination. The intuitive ways of thinking about it aren't the only ways, though; the article I link in my spoiler block gives the derivation from Bayes...
Fri Jan 23, 2015 10:44 pm UTC
Forum: Logic Puzzles
Topic: The infinite suburb and the teleporter breakdown.
Replies: 26
Views: 7213

### Re: The infinite suburb and the teleporter breakdown.

(0,k) can be reached in two hops for all k>2. The solution, though encouraging, isn't terribly enlightening. I've still no idea about the rest of our lattice. For k odd use the m,n,n+1 triples: (2k-1,2k(k-1),2k(k-1)+1) and (2k+1,2k(k+1),2k(k+1)+1) but...
Fri Jan 23, 2015 10:30 pm UTC
Forum: Logic Puzzles
Topic: Gambling with the magical genie
Replies: 27
Views: 7276

### Re: Gambling with the magical genie

Aside from calculating your personal "risk tolerance", the math here is surprisingly simple: We can invoke Laplace's Rule of Succession , which gives the probability of personally winning, given that you've observed n wins and no losses, as (n+1)/(n+2). So given a m...
Fri Dec 19, 2014 11:32 pm UTC
Forum: Logic Puzzles
Topic: The Labyrinth Puzzle (original xkcd)
Replies: 12
Views: 8485

### Re: The Labyrinth Puzzle (original xkcd)

Spoiler:
What's 2+2?
Then ask which door leads to freedom. They're guards, you're stuck in a labyrinth, surely you all have time for more than one question.
Sat Jun 29, 2013 3:02 pm UTC
Forum: Books
Topic: Recommend a book
Replies: 484
Views: 264911

### Re: Recommend a book

The Boy Who Loved Math: The Improbable Life of Paul Erdös is a gorgeous picture book about the mathematician Paul Erdos, full of math in-jokes and affirmation of the weird. It just came out. Cory Doctorow's review.
Mon Dec 17, 2012 8:43 pm UTC
Forum: Logic Puzzles
Topic: Create a perfect lossless compression algorithm
Replies: 21
Views: 5162

### Re: Create a perfect lossless compression algorithm

Yakk's solution is the one I had in mind, and Qaanol's (first) one is just as good. The other one looks like a promising avenue for cheats, too...
Mon Dec 17, 2012 6:09 pm UTC
Forum: Logic Puzzles
Topic: Create a perfect lossless compression algorithm
Replies: 21
Views: 5162

### Re: Create a perfect lossless compression algorithm

Yes, Bob knows when the transfer is over (otherwise I think this is impossible). And your spoilered analysis describes the sort of thing I'm looking for, and constitutes a proof that it's optimal...the rest of the challenge is coming up with an algorithm that actually does that. Obviously there are ...
Mon Dec 17, 2012 4:56 pm UTC
Forum: Logic Puzzles
Topic: Create a perfect lossless compression algorithm
Replies: 21
Views: 5162

### Create a perfect lossless compression algorithm

Alice and Bob have been contracted to transmit information over an expensive channel. Alice will be given a series of files, each consisting of exactly 1048576 random bits. Upon receiving each one, she can send whatever information she wants to Bob, at a cost of \$1 per bit. Bob must then recreate th...
Mon Dec 03, 2012 8:40 pm UTC
Forum: Logic Puzzles
Topic: What isn't the answer to this puzzle?
Replies: 13
Views: 3583

### Re: What isn't the answer to this puzzle?

Spoiler:
Mon Sep 10, 2012 2:14 am UTC
Forum: Logic Puzzles
Topic: Pennies in Boxes
Replies: 85
Views: 51786

### Re: Pennies in Boxes

Spoiler:
My girlfriend's solution: transport the box to a remote area, put down a flame resistant tarp, and burn it.
Thu Sep 06, 2012 10:24 pm UTC
Forum: Logic Puzzles
Topic: Pennies in Boxes
Replies: 85
Views: 51786

### Re: Pennies in Boxes

Spoiler:
First thought is to find an acid that reacts with cardboard but not metal. I know you can clean pennies with acid.
Fri Aug 31, 2012 3:39 pm UTC
Topic: 1102: "Fastest-Growing"
Replies: 85
Views: 21077

### Re: 1102: "Fastest-Growing"

So, what's the proper way to judge the fastest growing religion? I agree it has to be in absolute, not percentage terms. But it doesn't seem right to count children born into a religion as new members--having lots of kids isn't nearly as bullish a sign as having lots of converts. Once I was wearing ...
Fri Aug 03, 2012 4:08 am UTC
Topic: 1090: "Formal Languages"
Replies: 90
Views: 30061

### Re: 1090: "Formal Languages"

Scaling Everest was, by far, the most amazing and transformative experience of my life.
Sat Jun 30, 2012 2:00 am UTC
Forum: Logic Puzzles
Topic: A prison with an infinite number of cells
Replies: 28
Views: 8802

### Re: A prison with an infinite number of cells

Your solution to version 2 isn't the kind I intended, since it requires coordination on the part of the guards.
Fri Jun 29, 2012 12:30 pm UTC
Forum: Logic Puzzles
Topic: A prison with an infinite number of cells
Replies: 28
Views: 8802

### Re: A prison with an infinite number of cells

The obvious evil expansion of this: Version 1: You're responsible for infinitely many prisons, Prison 1, Prison 2, etc. Each Prison K has infinitely many cells, K-1, K-2, etc. each of which has one prisoner. You receive word that all but Prison 1 are to be closed down, and everyone must be relocated...
Mon Jun 11, 2012 11:54 am UTC
Forum: Logic Puzzles
Topic: Is This Even Possible?
Replies: 77
Views: 27048

### Re: Is This Even Possible?

OK, another modification of this puzzle. Assuming the words are 'da' and 'ja'. Ask God 1: "Is one of the following true: You are the liar, and if I were to ask you whether God 2 is the random God you would answer 'da'? You are the truthteller, and your answer to this qu...
Sat May 12, 2012 5:23 pm UTC
Forum: Logic Puzzles
Topic: Black Box Logic Gates.
Replies: 6
Views: 3784

### Re: Black Box Logic Gates.

It can't be done in fewer than
Spoiler:
3 tests. 2 tests give at best 2*4=8 bits of information, enough to distinguish between 2^8=256 possibilities. But there are 6!=720 possible permutations of the gates.
Tue May 01, 2012 9:45 pm UTC
Topic: My book/play/art: Hamlet and the Philosopher's Stone
Replies: 0
Views: 5478

### My book/play/art: Hamlet and the Philosopher's Stone

http://www.makefoil.com/Cover_small.jpg I just noticed that I seem to have never made a thread for this. Hamlet and the Philosopher's Stone is my completed Hamlet fan fic, available as an e-book. The play is a rewrite of Hamlet that preserves much of the original style, language, and plot, while in...
Tue May 01, 2012 7:56 pm UTC
Forum: Books
Topic: Comment on a book using xkcd 1049
Replies: 8
Views: 5179

### Re: Comment on a book using xkcd 1049

SlyReaper wrote:I don't think you need the "used without permission" there so long as you credit the source.

Probably not, I'm just slightly leery of making it look at all like I'm putting words in Randall's mouth.

Tue May 01, 2012 7:39 pm UTC
Forum: Books
Topic: Comment on a book using xkcd 1049
Replies: 8
Views: 5179

### Comment on a book using xkcd 1049

http://www.makefoil.com/HATPS_Bookshelf.png So, I think the main point of the comic was the witty way to comment on a book, not the specific commentary. To that end, I've made a site where you can generate your own version that says whatever you want about whatever book you want. Enjoy. Share your ...
Tue May 01, 2012 7:27 pm UTC
Topic: 1049: "Bookshelf"
Replies: 867
Views: 130967

### Re: 1049: "Bookshelf"

http://www.makefoil.com/HATPS_Bookshelf.png So, I think the main point of the comic was the witty way to comment on a book, not the specific commentary. To that end, I've made a site where you can generate your own version that says whatever you want about whatever book you want. Enjoy!
Thu Mar 29, 2012 6:52 am UTC
Forum: Logic Puzzles
Topic: The Disgruntled Alien Visitor
Replies: 9
Views: 5326

### Re: The Disgruntled Alien Visitor

You can get more mileage out of your questions by making "Maybe" a possible response. So once you've identified "Yes" and "No", and you have a partition of possible planspace into equiprobability chunks {A,B,C}, you can ask "Is it true that either your plan is...
Sun Mar 25, 2012 3:51 am UTC
Forum: Logic Puzzles
Topic: Imposter Puzzle
Replies: 69
Views: 19513

### Re: Imposter Puzzle

At the initial meeting, agree on a group password and an easy-to-perform hash algorithm . When a group meets, they sit in a circle, and each person chooses a random word on the spot and announces it. Everybody then calculates two hashes: the hash of their own word concatenated with the password, an...
Mon Mar 12, 2012 2:56 pm UTC
Forum: Books
Topic: Harry Potter and the Methods of Rationality
Replies: 1036
Views: 404317

### Re: Harry Potter and the Methods of Rationality

Mon Mar 12, 2012 5:44 am UTC
Topic: 1028: "Communication"
Replies: 107
Views: 44805

### Re: 1028: "Communication"

Princess Marzipan wrote:There is no way to make it clickable.

Here. Technique from Vaniver.
Sat Mar 10, 2012 9:28 pm UTC
Forum: Logic Puzzles
Topic: The solution is a two-digit number, part two
Replies: 4
Views: 2967

### Re: The solution is a two-digit fish, part two

Mod-Madness makes my puzzles even harder.
Sat Mar 10, 2012 4:48 pm UTC
Forum: Books
Topic: Harry Potter and the Methods of Rationality
Replies: 1036
Views: 404317

### Re: Harry Potter and the Methods of Rationality

Update March 12: He's reading HPMoR , thanks presumably to the fact that one out every twenty recs he's gotten so far was for it. Still no fan reviews for Luminosity or Hamlet and the Philosopher's Stone. First off, some good news. From an exchange on a Less Wrong thread, it appears EY was consider...
Fri Mar 09, 2012 11:56 pm UTC
Forum: Logic Puzzles
Topic: The solution is a two-digit number, part two
Replies: 4
Views: 2967

### Re: The solution is a two-digit number, part two

Ended wrote:
Spoiler:

Ding ding ding!
Fri Mar 09, 2012 12:52 am UTC
Forum: Logic Puzzles
Topic: The solution is a two-digit number, part two
Replies: 4
Views: 2967

### The solution is a two-digit number, part two

Part one here. Look in thy glass and tell the face thou viewest Time doth transfix the flourish set on youth. Those hours, that with gentle work did frame The lovely gaze where every eye doth dwell, Will play the tyrants to the very same That thou among the wastes of time must go. The point will co...
Sat Feb 18, 2012 4:27 am UTC
Forum: Books
Topic: Harry Potter and the Methods of Rationality
Replies: 1036
Views: 404317

### Re: Harry Potter and the Methods of Rationality

jobriath wrote:If anyone remembers this I'd be interested to read it again, though I've had no luck finding it yet.

http://lesswrong.com/lw/ld/the_hidden_complexity_of_wishes/
Wed Feb 15, 2012 7:35 pm UTC
Forum: Logic Puzzles
Topic: Elven Village Mayor
Replies: 22
Views: 6767

### Elven Village Mayor

You've decided to found a new Elven Village, where elves can journey to set up residence and live out their immortal lives free from all those plebeian non-elves. You've picked out a plot of land, surrounded it with an impenetrable wall, and now you keep the sole gate. You've sent out word, and soon...
Wed Feb 15, 2012 6:13 pm UTC
Forum: Books
Topic: Harry Potter and the Methods of Rationality
Replies: 1036
Views: 404317

### Re: Harry Potter and the Methods of Rationality

That's pretty clever. I think the heart of it is the idea that the final loop should seem like it could be the first loop, even though it's improbable. Of course, the whole idea of using an algorithm seems kind of cargo-cultish, since the Time-Turner is said not to operate by creating a series of ti...