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ForumsDiscussion Forum → An open question to Jon`C
An open question to Jon`C
2011-04-17, 1:24 AM #1
Does P = NP?
"it is time to get a credit card to complete my financial independance" — Tibby, Aug. 2009
2011-04-17, 2:18 AM #2
Depends if it's in a sealed box that you can't see into.
2011-04-17, 2:28 AM #3
Originally posted by Freelancer:
Does P = NP?


I don't know.
2011-04-17, 7:47 AM #4
An open question to Jon`C:

Does freelancer suck?
>>untie shoes
2011-04-17, 7:48 AM #5
I want my own thread too =[
2011-04-17, 8:02 AM #6
Originally posted by Freelancer:
Does P = NP?


If P = 0.5P and N = 2P, then, yes.
the idiot is the person who follows the idiot and your not following me your insulting me your following the path of a idiot so that makes you the idiot - LC Tusken
2011-04-17, 11:06 AM #7
Originally posted by Antony:
An open question to Jon`C:

Does freelancer suck?


At what?
2011-04-17, 11:11 AM #8
Making threads.
Bassoon, n. A brazen instrument into which a fool blows out his brains.
2011-04-17, 11:13 AM #9
Trying to be intellectual.
>>untie shoes
2011-04-17, 11:14 AM #10
Originally posted by Emon:
Making threads.
Yes.

Originally posted by Antony:
Trying to be intellectual.
Yes.
2011-04-17, 12:55 PM #11
Is there a punchline I'm missing here?
SnailIracing:n(500tpostshpereline)pants
-----------------------------@%
2011-04-17, 1:27 PM #12
http://en.wikipedia.org/wiki/P_versus_NP_problem
"I would rather claim to be an uneducated man than be mal-educated and claim to be otherwise." - Wookie 03:16

2011-04-17, 2:31 PM #13
Fun fact: the P?NP problem is the reason our currency comes in 0.01,0.05,0.10,0.25,1,5,10,20,100 denominations. We can use a polynomial-time greedy algorithm to count change, starting from the highest denomination to the lowest, and we get the smallest number of coins needed to form that change (exercise to prove.)

What happens if we choose arbitrary denominations?

e.g. if you have the denominations 0.01,0.20,0.21, make 0.60 in change.

Using the greedy algorithm, you take 2(0.21)+18(0.01), or 20 coins.
But the correct solution is clearly to take 3(0.20), or 3 coins, so the greedy algorithm is no longer sufficient to find an optimal solution.

When you allow arbitrary denominations, the problem becomes NP-complete. The greedy approach is linear in the number of denominations, but this problem is linear in the value of the amount of change that must be made. The value of a number, however, is in Theta(b^n) where b is the radix and n is the number of places. So the problem is exponential in the size of the input.

So here's the challenge for all of you: if you can find a way to quickly count change in an arbitrary money system, using the least number of coins, you have proven that P=NP.
2011-04-17, 7:03 PM #14
You left out the part about winning 1,000,000$
"Nulla tenaci invia est via"
2011-04-17, 9:03 PM #15
Jon'c out of curiosity, what is your IQ? I'm not being a smartass either, your just God damned gifted.
2011-04-17, 9:12 PM #16
IQ isn't really relative to actual intelligence. Mine is 136 and I'm almost always borderline retarded.
>>untie shoes
2011-04-17, 9:24 PM #17
I got 202 on an IQ test once by pure random guessing. I should have screenshotted that.
2011-04-17, 10:16 PM #18
Cool Matty, online IQ tests don't count.
>>untie shoes
2011-04-17, 10:51 PM #19
Well I sure hope not, after all, I got a 202 for guessing.
2011-04-18, 1:24 AM #20
Supposedly Richard Feynman had an IQ of 120. Antony is not smarter than Richard Feynman.
Bassoon, n. A brazen instrument into which a fool blows out his brains.
2011-04-18, 2:30 AM #21
Hey guys, doesn't matter what you have, it's what you do with it.
He said to them: "You examine the face of heaven and earth, but you have not come to know the one who is in your presence, and you do not know how to examine the present moment." - Gospel of Thomas
2011-04-18, 4:08 AM #22
Quote:
Supposedly Richard Feynman had an IQ of 120. Antony is not smarter than Richard Feynman.
120 barely counts as smart.
2011-04-18, 5:26 AM #23
Quote:
So here's the challenge for all of you: if you can find a way to quickly count change in an arbitrary money system, using the least number of coins, you have proven that P=NP.


But how are you defining "quickly"? Developing an alogorithm to give you the correct answer isn't difficult.
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2011-04-18, 6:47 AM #24
Originally posted by Tenshu2.0:
Hey guys, doesn't matter what you have, it's what you do with it.


motion of the ocean, blah blah
TAKES HINTS JUST FINE, STILL DOESN'T CARE
2011-04-18, 10:02 AM #25
Originally posted by Ni:
But how are you defining "quickly"? Developing an alogorithm to give you the correct answer isn't difficult.


Polynomial time. And yes. Actually, it is _very_ difficult. We aren't talking about verifying that an answer is correct, and we aren't talking about heuristics that produce decent-but-suboptimal results. And we certainly aren't talking about braindead brute force algorithms that run in superpolynomial time. We are talking about producing the optimum solution for all inputs in polynomial time.

Jon: I was under the impression that solving one NP-complete problem wasn't proof that P = NP. Is it?
"it is time to get a credit card to complete my financial independance" — Tibby, Aug. 2009
2011-04-18, 10:08 AM #26
Originally posted by Freelancer:
Jon: I was under the impression that solving one NP-complete problem wasn't proof that P = NP. Is it?


If you can find one polynomial-time algorithm for an NP-complete problem, you have proven that P=NP.
2011-04-18, 10:32 AM #27
I was really hoping for Freelancer to ask something that only Jon`C could answer. Rather than something which everyone who has ever written an algorithm should know about.
Detty. Professional Expert.
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2011-04-18, 10:54 AM #28
You should have known better.
TAKES HINTS JUST FINE, STILL DOESN'T CARE
2011-04-18, 12:12 PM #29
Man, P versus NP, something I haven't given any real thought to since sophomore year of college.
2011-04-18, 12:18 PM #30
Originally posted by Darth:
Man, P versus NP, something I haven't given any real thought to.


thats about where that statement stops for me.
Welcome to the douchebag club. We'd give you some cookies, but some douche ate all of them. -Rob
2011-04-18, 12:37 PM #31
Originally posted by Darth:
Man, P versus NP, something I haven't given any real thought to since sophomore year of college.


Are you being sarcastic, or are you really not interested in the theory of computation?
2011-04-18, 12:53 PM #32
Originally posted by Detty:
I was really hoping for Freelancer to ask something that only Jon`C could answer. Rather than something which everyone who has ever written an algorithm should know about.
I'll ask one then!

Can you tell us what plans the Goa'uld have in store for us, so that we may prepare for a plan of our own to foil them?
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2011-04-18, 2:07 PM #33
Originally posted by Detty:
I was really hoping for Freelancer to ask something that only Jon`C could answer. Rather than something which everyone who has ever written an algorithm should know about.


Obviously I don't expect him to have the solution, but I was curious how he'd answer. I expected him to say no or at least 'probably not.'
"it is time to get a credit card to complete my financial independance" — Tibby, Aug. 2009
2011-04-18, 2:29 PM #34
There have been just as many false proofs for P=NP as there have been for P≠NP. Intuitively I don't see how they can possibly be equal, but the only correct answer to the question is "I don't know."
2011-04-18, 8:34 PM #35
I think the real question is, would a computer answer "I don't know"?
"I would rather claim to be an uneducated man than be mal-educated and claim to be otherwise." - Wookie 03:16

2011-04-19, 1:35 AM #36
I don't like IQ tests, because I consider them unreliable when it comes to consistency. I've done a couple of IQ tests (standardized and supervised ones, not online, though keep in mind that Finnish tests are a lot easier since Finns are generally less intelligent, which is mostly attributed to hereditary factors...the average Finn would be mildly retarded by American standards, for example) with considerably different results, because the first time I was so drugged up that it affected my cognitive skills.
Looks like we're not going down after all, so nevermind.

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