## Search found 206 matches

Wed Jan 23, 2013 8:22 pm UTC
Forum: Logic Puzzles
Topic: Flow
Replies: 17
Views: 12457

### Re: Flow

The "corners" idea he suggests doesn't seem to work very often. Am I misunderstanding something? The corners idea works because of uniqueness. Basically, in usual logic puzzles, you're guaranteed that there is one and only one solution to each puzzle. In most puzzle types, there's no way ...
Tue Jan 22, 2013 4:59 pm UTC
Forum: Logic Puzzles
Topic: Flow
Replies: 17
Views: 12457

### Re: Flow

Topological rules help a lot. Especially when you have, say, two matching dots that are both on an edge - you know their path has to loop around the other dots in such a way that it doesn't block any pairs off. Here's a Numberlink Solving Primer courtesy of Palmer Mebane. (Numberlink is almost exact...
Sat Jan 19, 2013 8:11 pm UTC
Forum: Computer Science
Topic: Solving the Octopuszle
Replies: 15
Views: 13436

### Re: Solving the Octopuszle

A recursion depth of 20 means that you're hardly even getting past the first row, so something is probably wrong with your block-placing algorithm. Yep, your check function has a bug. You copied the DL part from the UR part but forgot to change it. So your code never places a block past the first ro...
Sat Jan 19, 2013 4:24 pm UTC
Forum: Logic Puzzles
Topic: New abstract game : Sozee
Replies: 24
Views: 6156

### Re: New abstract game : Sozee

I found a 7x7 board with k=8. I can get 8 blue squares and 9 red squares maximum.
Spoiler:

Code: Select all

`R..R..R.BBB....BBB...RBBR..R..............R..R..R`
Thu Jan 17, 2013 10:21 pm UTC
Forum: Forum Games
Topic: Misquote the famous
Replies: 15
Views: 1809

### Re: Misquote the famous

Yup, you're up next!
Thu Jan 17, 2013 10:20 pm UTC
Forum: Forum Games
Topic: The "I would rather" Game [possible trigger warning]
Replies: 73
Views: 9260

### Re: The "I would rather" Game [possible trigger warning]

I would rather be bitten by a non-poisonous snake than be in a room (for a meeting, lesson, etc.) for a quarter of an hour before realising I'm in the wrong place and having to leave.
Thu Jan 17, 2013 8:43 pm UTC
Forum: Logic Puzzles
Topic: Find the 2013th digit after the decimal point
Replies: 2
Views: 2144

### Re: Find the 2013th digit after the decimal point

I get 1. The decimal expansion of that square root is really weird. A bunch of 3's, then 6's, then 9's, then 6's again... I guess that's because we're calculating sqrt(1/9-1/(9*10 n )), and the pattern comes from the expansion of the Taylor series for the squ...
Wed Jan 16, 2013 5:03 pm UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes [solutions]
Replies: 29
Views: 8955

### Re: Solve ALL of the Mazes [solutions]

That proof is incredible, notzeb! It took me a little while to convince myself that the steady-state distribution was as you said, but I believe it checks out. For the bounds, intuitively, it seems to me that Markov chains should converge exponentially to the steady-state distribution. In other word...
Tue Jan 15, 2013 3:37 am UTC
Forum: Forum Games
Topic: The "I would rather" Game [possible trigger warning]
Replies: 73
Views: 9260

### Re: The "I would rather" Game [possible trigger warning]

I wouldn't really mind kicking the wall with my shoes on.
Wear clothes made of live calapitters caterpillars.
Tue Jan 15, 2013 3:28 am UTC
Forum: Forum Games
Topic: Misquote the famous
Replies: 15
Views: 1809

### Re: Misquote the famous

Spoiler:
Albert Einstein?
Einstein wrote:"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones."
If this is correct, then my misquote is: "Eliminate all other factors, and whatever remains, however improbable, must be [a prime number]."
Mon Jan 14, 2013 8:08 pm UTC
Forum: Mathematics
Topic: [HOMEWORK] Arccot problem
Replies: 3
Views: 1774

### Re: [HOMEWORK] Arccot problem

HINT: There are a bunch of inverse cotangents there. Try taking the cotangent of both sides. Also, when you're trying to reduce each side, remember that cot = 1/tan. In general, sin, cos, and tan are easier to work with than sec, csc, and cot (just because they crop up more often, so you have patter...
Mon Jan 14, 2013 2:54 pm UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes [solutions]
Replies: 29
Views: 8955

### Re: Solve ALL of the Mazes [solutions]

Wow, that looping example is awesome, ThirdParty. Seeing what you can do with just 3 small mazes gives me hope of finding a full counterexample after all. (Of course, it might turn out that there is always a way to solve every maze at once, but after seeing that, I'm leaning towards it being impossi...
Sat Jan 12, 2013 3:58 am UTC
Forum: Forum Games
Topic: Maximize the post:views ratio! (if you look, you must post)
Replies: 36919
Views: 2374858

### Re: Maximize the post:views ratio! (if you look, you must p

Why did the chicken cross the road? To maximize the walks:views ratio.
Fri Jan 11, 2013 5:53 pm UTC
Forum: Forum Games
Topic: Can You Count?
Replies: 2422
Views: 238055

### Re: Can You Count?

The first pseudoprime to base 3. That is, since 3^90 == 1 (mod 91), the Fermat primality test on base 3 falsely tells you that 91 is prime, and this is the first time it's wrong. Also the first strong pseudoprime to 17 distinct bases, the worst of any number until 341. Also the only number below 100...
Thu Jan 10, 2013 3:47 am UTC
Forum: Forum Games
Topic: Can You Count?
Replies: 2422
Views: 238055

### Re: Can You Count?

Wed Jan 09, 2013 7:56 pm UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes [solutions]
Replies: 29
Views: 8955

### Re: Solve ALL of the Mazes [solutions]

Yeah, I'm worried about situations like this: temp.png No matter how we solve the maze on the left, we're always going to get stuck in a dead-end in the maze on the right. Of course, we can just work our way out again. But if there's more than just these two mazes, with really circuitous paths, then...
Wed Jan 09, 2013 12:14 am UTC
Forum: Mathematics
Topic: Anybody know the name for this?
Replies: 4
Views: 1040

### Re: Anybody know the name for this?

Tue Jan 08, 2013 9:45 pm UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes [solutions]
Replies: 29
Views: 8955

### Re: Solve ALL of the Mazes [solutions]

That is indeed the solution to the (Medium) version, good job! Dudiobugtron: Why does it also solve the (Super Hard, probably) version? It looks to me like, in Deathdefy's solution, when the robot navigates to the exit as if it were hypothetically in the "second" maze, it might wander off ...
Mon Jan 07, 2013 4:14 am UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes
Replies: 0
Views: 3239

### Solve ALL of the Mazes

You're minding your own business in the Land of Geometry, when suddenly a stupid robot runs up to you with a pen and paper. "Quick!" it squeaks. "Can you give me directions through the Featureless Maze?" Oh, dear. This is the third time today a robot has mistaken you for one of t...
Mon Jan 07, 2013 4:14 am UTC
Forum: Logic Puzzles
Topic: Solve ALL of the Mazes [solutions]
Replies: 29
Views: 8955

### Solve ALL of the Mazes [solutions]

Remember that the robot only understands a simple list of ←↑↓→ arrows! Don't try to feed it the left-hand-on-the-wall rule, or God forbid, Dijkstra's algorithm.

The (Medium) version is fairly classic, but the (Super Hard, Probably) version is original as far as I know.
Sat Jan 05, 2013 4:02 pm UTC
Forum: Forum Games
Topic: Corrupt-a-wish
Replies: 26069
Views: 2439393

### Re: Corrupt-a-wish

Granted. However, after using the motivation to finish your everyday tasks, you find yourself with absolutely nothing to do. Since your new-found motivation isn't letting you relax on Youtube videos or forum games anymore, you become extremely frustrated and bored. I wish that I could make plants gr...
Sat Jan 05, 2013 3:46 pm UTC
Forum: Forum Games
Topic: Corrupt-a-wish
Replies: 26069
Views: 2439393

### Re: Corrupt-a-wish

Granted. They are knuckle sandwiches.

I wish for a pony.
Fri Jan 04, 2013 10:36 pm UTC
Forum: Mathematics
Topic: C^k maps
Replies: 6
Views: 1276

### Re: C^k maps

Is f(x)=x3 a counterexample at x=0, or am I missing something?
Wed Jan 02, 2013 3:09 am UTC
Forum: Mathematics
Topic: Powers of 2 and 3
Replies: 7
Views: 1846

### Re: Powers of 2 and 3

I'd appreciate it if someone could show me how to show that 3^p - 1 = 2^n only has the solutions (p,n) = (1,1) and (2,3)). Sure. In general, the strategy for proving this sort of fact is to take the equation modulus lots of random numbers, and then somehow use factorization to either get an infinit...
Mon Dec 31, 2012 3:38 pm UTC
Forum: Forum Games
Topic: Chess
Replies: 33
Views: 6802

### Re: Chess

9...Nd7 http://www.apronus.com/chess/stilldiagram.php?d=PRN__K__RPPP__PPP_____B_______B______Q_____p_bn__pp_n_pppr__qkb_r0&w=8&h=8&a=false%2C0%2CPRN__K__RPPP__PPP_____B_______B______Q_____p_bn__pp_n_pppr__qkb_r0/ Black appears to be up a piece. How (un)fortunate. I'd be interested in a o...
Mon Dec 31, 2012 3:34 am UTC
Forum: Mathematics
Topic: Does it actually work? (encription type number puzzle)
Replies: 19
Views: 9953

### Re: Does it actually work? (encription type number puzzle)

I was half-joking about this RSA-5 cipher being the next ROT-13. :wink: It is rather cute, though. On the other hand... look at how secure it is! If we were to encrypt a random message like "AZALEA MAYHEM: ALERT ARMY" using RSA-5, the result would be just as hard to crack as if we had used...
Sat Dec 29, 2012 5:48 pm UTC
Forum: Mathematics
Topic: Does it actually work? (encription type number puzzle)
Replies: 19
Views: 9953

### Re: Does it actually work? (encription type number puzzle)

Personally, I learned RSA (and a bunch of other stuff related to number theory and codes) from a cryptography course in college. Cryptography is mainly math, but there's quite a bit of computer science in there too, especially when you want to analyze different ways that a computer program can attac...
Fri Dec 28, 2012 6:25 pm UTC
Forum: Mathematics
Topic: Does it actually work? (encription type number puzzle)
Replies: 19
Views: 9953

### Re: Does it actually work? (encription type number puzzle)

It's actually just RSA with a key of 5. To encrypt, take each number to the fifth power mod 26. Decryption is similar, and to find the decryption key, we take 5 -1 (mod phi(26)=12), which is also 5. So the decryption process happens to be the same as the encryption process (It's the new ROT13!). It'...
Sun Dec 23, 2012 10:45 pm UTC
Forum: Forum Games
Topic: Mornington Crescent
Replies: 2697
Views: 270665

### Re: Mornington Crescent

Wow, lots of drama here! All this game joining/unresigning has made it really tricky to even start pruning the tree of variations. Just on instinct: I'll use the initiative flicky's move granted me, letting me finally ride to one of my favorite stations in the game: King's Cross St. Pancras . Say wh...
Sun Dec 23, 2012 6:24 pm UTC
Forum: The Help Desk
Topic: HTML form processing (with PHP?) gives 404
Replies: 2
Views: 2148

### HTML form processing (with PHP?) gives 404

I'm new to website building, and I'm trying what seems like a simple task: letting someone fill out a form and then processing it on the next page. Unfortunately it fails before even getting that far. I have no idea why the following doesn't work. On the page with the form, testing.html, is this HTM...
Sat Dec 22, 2012 3:09 am UTC
Forum: Forum Games
Topic: Mornington Crescent
Replies: 2697
Views: 270665

### Re: Mornington Crescent

I closed the Dollis Hill loop when I moved to Tottenham Court Road , so people aren't in a dollis hill loop. Good point! And to think I was just about to blindly follow along with the loop. First of all, Pass Snow Cone to flicky1991 - he'll have better use for it in White City, and right now my mai...
Fri Dec 21, 2012 3:05 am UTC
Forum: Mathematics
Topic: Modular matrix power for very large exponents
Replies: 2
Views: 2013

### Re: Modular matrix power for very large exponents

First of all, we only need to solve the problem when m is a prime power, so let m=p k . (Hopefully your m is small enough to factorize; if it's not, I have no idea how to do this efficiently.) Now set A=PJP -1 where J is in Jordan Canonical Form. It's easy to find large powers of a matrix in Jordan ...
Fri Dec 21, 2012 1:15 am UTC
Forum: Forum Games
Topic: Mornington Crescent
Replies: 2697
Views: 270665

### Re: Mornington Crescent

No way that's true. No freakin' way. ...You were keeping all this in reserve just for a Strawberry Classic, weren't you? I have no words. Well, not much I can do now. East Finchley with synergy, but at this rate I doubt I'll even have a chance to deploy my Snow Cone. Time to sit back and watch the f...
Fri Dec 21, 2012 12:29 am UTC
Forum: Forum Games
Topic: Can you produce [X] in less than 15 seconds?
Replies: 7692
Views: 743820

### Re: Can you produce [X] in less than 15 seconds?

No way.

Something melted?
Fri Dec 21, 2012 12:25 am UTC
Forum: Forum Games
Topic: The "I would rather" Game [possible trigger warning]
Replies: 73
Views: 9260

### Re: The "I would rather" Game [possible trigger warning]

I would rather climb Mount McKinley wearing only shorts and a T-shirt than French-kiss a giraffe.
Thu Dec 20, 2012 7:56 pm UTC
Forum: Forum Games
Topic: Mornington Crescent
Replies: 2697
Views: 270665

### Re: Mornington Crescent

Clever. I completely forgot about the possibility of flip spins. And I didn't expect to be so cramped in on turn two. This makes things uncomfortable, but I believe I should just stick to my original plan and hope it pulls through. Buy item: Snow Cone (tickets -1) . I would go for the Smartphone, bu...
Thu Dec 20, 2012 7:28 pm UTC
Forum: Forum Games
Topic: Count to 1 1000 times!
Replies: 1000
Views: 164696

### Re: Count to 1 1000 times!

Half of the blank: ar___rk
Thu Dec 20, 2012 5:30 pm UTC
Forum: Forum Games
Topic: Mornington Crescent
Replies: 2697
Views: 270665

### Re: Mornington Crescent

In a Classic game like this, I like to start residential. West Finchley.

(Of course this is a dubious opener under Standard rules, but since the shopping district penalty was only established post-2003, it opens up nice Item play in Classic without incurring the usual ticket drought.)
Wed Dec 19, 2012 4:11 pm UTC
Forum: General
Topic: ITT: We make xkcd slightly worse.
Replies: 8668
Views: 1798783

### Re: ITT: We make xkcd slightly worse.

Lemme try my hand at one of these...

1149 (mirror hosting)

Black Hat Guy, make way for Black Hat Witch.
Wed Dec 19, 2012 4:25 am UTC
Forum: Logic Puzzles
Topic: Find a power outlet in a dark room
Replies: 22
Views: 8377

### Re: Find a power outlet in a dark room

Unless we can feel electromagnetic fields, I think we have to comprehensively search everywhere. But there's a shortcut for philip's solution: Presumably at least one leg of one chair has a rather flat side. Instead of groping with our hands, we can drag that flat edge along entire swathes of the wa...