User Kaveh

454 votes

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What is the definition of P, NP, NP-complete and NP-hard?

answered Feb 7, 2013 at 4:00

227 votes

What is the definition of P, NP, NP-complete and NP-hard?

answered Dec 5, 2013 at 22:19

71 votes

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Are there subexponential-time algorithms for NP-complete problems?

answered Feb 15, 2013 at 16:35

60 votes

How not to solve P=NP?

answered May 17, 2012 at 2:13

47 votes

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Knapsack problem -- NP-complete despite dynamic programming solution?

answered Mar 31, 2012 at 5:52

36 votes

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Why are there more non-computable functions than computable ones?

answered Feb 10, 2013 at 9:08

28 votes

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Are there NP problems, not in P and not NP Complete?

answered May 12, 2012 at 21:25

23 votes

Why is quicksort better than other sorting algorithms in practice?

answered Mar 6, 2012 at 19:19

23 votes

Why is Relativization a barrier?

answered Nov 18, 2012 at 0:26

21 votes

Is there a "natural" undecidable language?

answered Mar 10, 2012 at 5:46

20 votes

Why are computable functions also called recursive functions?

answered Jan 13, 2016 at 1:06

19 votes

Why, really, is the Halting Problem so important?

answered Nov 11, 2014 at 8:29

19 votes

How to prove that a language is not context-free?

answered Mar 13, 2012 at 2:11

18 votes

How does one know which notation of time complexity analysis to use?

answered Mar 7, 2012 at 1:58

18 votes

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Sub language is not Turing-recognizable, or could it be?

answered Apr 22, 2012 at 3:29

18 votes

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If A is mapping reducible to B then the complement of A is mapping reducible to the complement of B

answered Apr 26, 2012 at 22:10

15 votes

Turing machine - infinite tape - does that thing exist?

answered Jan 13, 2016 at 1:47

14 votes

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What is the time complexity of generating n-th prime number?

answered Mar 22, 2013 at 5:16

14 votes

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How to prove that a constrained version of 3SAT in which no literal can occur more than once, is solvable in polynomial time?

answered May 15, 2012 at 18:16

14 votes

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Is Karp Reduction identical to Levin Reduction

answered Jul 12, 2012 at 4:32

13 votes

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Decision problem such that any algorithm admits an exponentially faster algorithm

answered Mar 13, 2012 at 17:02

12 votes

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Turing complete and computational power

answered Sep 26, 2012 at 6:21

12 votes

Concrete understanding of difference between PP and BPP definitions

answered Feb 14, 2013 at 8:39

12 votes

What is meant by an oracle separation between classes $\mathsf{BPP}$ and $\mathsf{BQP}$?

answered Jul 31, 2013 at 2:35

12 votes

Why is writing down mathematical proofs more fault-proof than writing computer code?

answered Dec 12, 2017 at 12:52

11 votes

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Are there any specific problems known to be undecidable for reasons other than diagonalization, self-reference, or reducibility?

answered Jan 3, 2016 at 10:00

11 votes

Clear, intuitive derivation of the fixed-point combinator (Y combinator)?

answered Feb 10, 2013 at 23:38

11 votes

P-Completeness and Parallel Computation

answered Apr 21, 2012 at 20:26

11 votes

What is required for universal analogue computation?

answered Apr 15, 2012 at 22:40

11 votes

Accepted

Why is this example a regular language?

answered May 7, 2012 at 4:04

Stack Exchange Network

151 Answers

What is the definition of P, NP, NP-complete and NP-hard?

What is the definition of P, NP, NP-complete and NP-hard?

Are there subexponential-time algorithms for NP-complete problems?

How not to solve P=NP?

Knapsack problem -- NP-complete despite dynamic programming solution?

Why are there more non-computable functions than computable ones?

Are there NP problems, not in P and not NP Complete?

Why is quicksort better than other sorting algorithms in practice?

Why is Relativization a barrier?

Is there a "natural" undecidable language?

Why are computable functions also called recursive functions?

Why, really, is the Halting Problem so important?

How to prove that a language is not context-free?

How does one know which notation of time complexity analysis to use?

Sub language is not Turing-recognizable, or could it be?

If A is mapping reducible to B then the complement of A is mapping reducible to the complement of B

Turing machine - infinite tape - does that thing exist?

What is the time complexity of generating n-th prime number?

How to prove that a constrained version of 3SAT in which no literal can occur more than once, is solvable in polynomial time?

Is Karp Reduction identical to Levin Reduction

Decision problem such that any algorithm admits an exponentially faster algorithm

Turing complete and computational power

Concrete understanding of difference between PP and BPP definitions

What is meant by an oracle separation between classes $\mathsf{BPP}$ and $\mathsf{BQP}$?

Why is writing down mathematical proofs more fault-proof than writing computer code?

Are there any specific problems known to be undecidable for reasons other than diagonalization, self-reference, or reducibility?

Clear, intuitive derivation of the fixed-point combinator (Y combinator)?

P-Completeness and Parallel Computation

What is required for universal analogue computation?

Why is this example a regular language?