Category: Uncategorized

Problem Detail: I am studying algorithms from CLRS book. I try to understand the difference between probability of hiring the $i$th person out of $n$ and probability of hiring the $i$th person out of $n$ persons based on ranks. Using the Read More …

Problem Detail: I’m looking for an algorithm that provides a canonical string for a given colored graph. Ie. an algorithm that returns a string for a graph, such that two graphs get the same string if and only if they are Read More …

Problem Detail: COQ is an interactive theorem prover that uses the calculus of inductive constructions, i.e. it relies heavily on inductive types. Using those, discrete structures like natural numbers, rational numbers, graphs, grammars, semantics etc. are very concisely represented. However, since Read More …

Problem Detail: It was asked in an exam why a color video compress better than a black and white (grayscale) video using MPEG but can’t find anything explaining it. In other words, we would apparently get a better compression ratio when Read More …

Problem Detail: $L_1 = {a^mb^nc^{m+n}: n,m>1}$ I know $L_1$ is CFL and works with a pushdown automata. $L_2 = {a^nb^nc^{2n}: n>1}$ The language $L_2$ should also be a CFL because it looks similar, but in my book $L_2$ is not a Read More …

Problem Detail: I have that language $S={a^n b^m c^mmid n,m geq 0}$. How can I prove with the pumping lemma that it isn’t regular? Can I use the concatenation closure and say that it’s the language $L_1 = {a^nmid ngeq0}$ and Read More …

Problem Detail: Let $L = {a^n mid n ge 0}$, where $a^0 = epsilon$ and $a^n = a^{n-1}a$ for all $n ge 1$. Thus $L$ consists of sequences of $a$ of all lengths, including a sequence of length $0$. Let $L_2$ Read More …

Problem Detail: I’m trying to answer this question: Let $S$ be the strings $langle P rangle$ accepted by the Turing Machine $P$ with input alphabet ${a,b}$, where $P$ accepts an infinite number of strings beginning with $a$ and a finite number Read More …

Problem Detail: Is there any example that anybody could come up with that shows Prim’s algorithm does not always give the correct result when it comes knowing the minimal spanning tree. Asked By : fudu Answered By : Kaya For any un-directed graph Read More …

Problem Detail: There is something I don’t understand. In the Subset Sum problem, in the Dynamic Programming solution, because of binary representation of the sum T, we say it is pseudo-polynomial in run time; we must sum in the worst case Read More …