Stack Overflow
Stack Overflow

Questions tagged [p-np]

Used for questions about the P versus NP problem.

The P versus NP problem is a major unsolved problem in computer science. Informally, it asks whether every problem whose solution can be quickly verified by a computer can also be quickly solved by a computer. (from wikipedia)

32 questions
249
votes
6 answers

What's "P=NP?", and why is it such a famous question?

The question of whether P=NP is perhaps the most famous in all of Computer Science. What does it mean? And why is it so interesting? Oh, and for extra credit, please post a proof of the statement's truth or falsehood. :)
raldi
  • 19,496
  • 29
  • 73
  • 85
67
votes
7 answers

Explain the proof by Vinay Deolalikar that P != NP

Recently there has been a paper floating around by Vinay Deolalikar at HP Labs which claims to have proved that P != NP. Could someone explain how this proof works for us less mathematically inclined people?
Nixuz
  • 3,265
  • 3
  • 35
  • 43
30
votes
6 answers

NP-hard problems that are not NP-complete are harder?

From my understanding, all NP-complete problems are NP-hard but some NP-hard problems are known not to be NP-complete, and NP-hard problems are at least as hard as NP-complete problems. Is that mean NP-hard problems that are not NP-complete are…
Nicky
  • 309
  • 1
  • 3
  • 3
19
votes
5 answers

Why are NP problems called that way (and NP-hard and NP-complete)?

Really.. I'm having the last test for graduation this Tuesday, and that's one of the things I just never could understand. I realize that a solution for NP problem can be verfied in polynomial time. But what does determinism has to do with that? And…
Oren A
  • 5,686
  • 5
  • 39
  • 59
17
votes
15 answers

What would a P=NP proof be like, hypothetically?

Would it be an polynomial time algorithm to a specific NP-complete problem, or just abstract reasonings that demonstrate solutions to NP-complete problems exist? It seems that the a specific algoithm is much more helpful. With it, all we'll have to…
Saobi
  • 13,579
  • 25
  • 67
  • 79
10
votes
4 answers

"Finding all the code in a given binary is equivalent to the Halting problem." Really?

Was just reading the highly voted question regarding Emulators and the statement It's been proven that finding all the code in a given binary is equivalent to the Halting problem. Really stuck out at me. Surely that can't be true? Isn't it…
Maxim Gershkovich
  • 42,124
  • 39
  • 134
  • 227
9
votes
7 answers

What is missing for this P != NP proof?

I tried to recover a password. When thinking of this I recognized that the problem "password recovery" is a very nice example of a NP problem. If you know the password it's very easy to verify it in polynomial time. BUT if you don't know the…
gruenewa
  • 1,578
  • 9
  • 16
8
votes
1 answer

P=NP: What are the most promising methods?

I know that P=NP has not been solved up to now, but can anybody tell me something about the following: What are currently the most promising mathematical / computer scientific methods that could be helpful to tackle this problem? Or are there even…
phimuemue
  • 30,699
  • 8
  • 74
  • 109
4
votes
2 answers

What are NP problems?

I read the article on wikipedia but could not understand what exactly are NP problems. Can anyone tell me about them and also what is relation of them with P Problems?
Shubham
  • 16,795
  • 17
  • 56
  • 84
3
votes
3 answers

P-NP problems solved? FindBugs solves the halting prob?

There is a tool called FindBugs it can detect infinite never ending loops in a given program/ code base. This implies FindBugs can detect if a program will end or not by analyzing the code. Halting problem is the problem defining that: Given a…
cornercoder
  • 276
  • 1
  • 4
  • 15
3
votes
2 answers

can some sorting be P, NP, and NP-Complete?

I am quite confused, and this is my thought after some reading: P is in NP and NP is in NP-Complete. Therefore, all P could be in NP and NP-Complete? Does that mean there are sorting algorithms that could be NP and NP-Complete? Hope this…
Chaos
  • 167
  • 2
  • 12
2
votes
1 answer

Primes in P - what about running till the sqrt?

I'm learning about P and NP. I've read that the problem of deciding if a given number is prime is a problem in P, which means that it has a polynomial-time algorithm which solves it. I've also read that this fact was proven in 2002, with the…
Programmer
  • 700
  • 1
  • 9
  • 15
2
votes
2 answers

Would an exponential lower bound on an NP-complete language prove P does not equal NP?

If someone were able to prove an exponential lower bound for a NP-complete problem, would that prove that P ≠ NP?
Romantic Amaj
  • 93
  • 1
  • 7
1
vote
2 answers

Ng Module watch in angular 6 not updates the html page

Actually I am working alongside without SharePoint with Pnp Js Rest Api . I am hosting the bundled files on SharePoint itself.. When i do ng build --watch its observing the changes but isn't reflected on the html files after build..
suriya prakash
  • 47
  • 5
1
vote
1 answer

Reduction of A to B : True or False

There are two statements: If a decision problem A is polynomial-time reducible to a decision problem B (i.e., A≤ pB ), and B is NP-complete, then A must be NP-complete. And: If a decision problem B is polynomial-time reducible to a decision problem…
Jay Patel
  • 1,156
  • 6
  • 15
  • 35
1
2 3