Problem Detail: I read on the site on how to use the pumping lemma but still I don’t what is wrong with way I’m using it for proving that the following language is not a regular language: $L = {a^ib^jc^k mid Read More …
Category: Uncategorized
Fast k mismatch string matching algorithm
Problem Detail: I am looking for a fast k-mismatch string matching algorithm. Given a pattern string P of length m, and a text string T of length n, I need a fast (linear time) algorithm to find all positions where P Read More …
What is dynamic programming about?
Problem Detail: Sorry in advance if this question sounds dumb… As far as I know, building an algorithm using dynamic programming works this way: express the problem as a recurrence relation; implement the recurrence relation either via memoization or via a Read More …
Intersection/Union of recursively enumerable languages that aren’t decidable?
Problem Detail: For $L_1, L_2 $ and $L_1 in RE $ and $ L_1notin R$ and $L_2 in RE $ and $ L_2notin R$ I was asked to prove/disprove if the following can occur: $L_1 cap L_2 in R$ $L_1 cup Read More …
Would proving P≠NP be harder than proving P=NP?
Problem Detail: Consider two possibilities for the P vs. NP problem: P=NP and P$neq$NP. Let Q be one of known NP-hard problems. To prove P=NP, we need to design a single polynomial time algorithm A for Q and prove that A Read More …
How is the rule 110 Turing complete?
Problem Detail: I’ve read the wikipedia page for rule 110 in cellular automata, and I more or less know how they work (a set of rules decides where to draw the next 1 or 0). I’ve just read they’re Turing complete, Read More …
What is the difference between decidability and computability?
Problem Detail: If they are different, what are the typical problems in each that do not fall on the other category? Or are the mutually exclusive or does one completely capture the other? Asked By : sdfasdgasg Answered By : Kaveh A function Read More …
how to draw a complement of a Turing Machine?
Problem Detail: I am now pretty confident on how I would turn something into a Turing Machine. Now my question is how do you convert TM into a complement of a Turing Machine. From what I can remember in Finite Automata, Read More …
What are lattices used for?
Problem Detail: Wikipedia says: Complete lattices appear in many applications in mathematics and computer science Is it just referring to the fact that the standard Boolean algebra used in computation is a complete lattice? Is there anything we gain by working Read More …
Is there an undecidable finite language of finite words?
Problem Detail: Is there a need for $Lsubseteq Sigma^*$ to be infinite to be undecidable? I mean what if we choose a language $L’$ be a bounded finite version of $Lsubseteq Sigma^*$, that is $|L’|leq N$, ($N in mathbb{N}$), with $L’ Read More …
