Author: ignougroup

Problem Detail: Given an adjacency matrix $A_G$ of an undirected graph $G$, it is easy and straightforward to compute the characteristic polynomial $chi_G(lambda)$. What about the other way around? The problem can be formulated as follows. Problem Given a polynomial $P$, Read More …

Problem Detail: I was reading about Turing machines and realized I’m not sure about the difference between the following scenario. Given the alphabet $Sigma = {a, b }$, we have the following assertions: $a in R $ ${a} in R$ I Read More …

Problem Detail: For instance, given the polynomial expression $xy + x + y + 1$ it will output $(x+1)(y+1)$. Thanks! Asked By : Fruitful Approach Answered By : user2566092 “Brute-force” in the context of factoring polynomials may involve factoring of integers, which is Read More …

Problem Detail: I have a weighted digraph graph $G = (V,E)$ where the weights are positive and negative integers. The graph $G$ is not necessarily acyclic. The question is: given 2 nodes $v_1$ and $v_2$, is there a path from $v_1$ Read More …

Problem Detail: I am trying to generate a $n$-bit gray code where I can specify two strings $s$ and $t$ that must be consecutive in that gray code. I know that there are ways to generate specific codes (such has the Read More …

Problem Detail: I know that all NP-complete problems can be reduced to each other, but how about NP-hard problems? Can all NP-hard problems be reduced to one another? Asked By : user3590783 Answered By : sashas The answer to your question is no. Read More …

Problem Detail: I have a file that has a number (a positive integer) on each row. Given a number $q$, I want to find a value that’s a sum of some 8 numbers in the file, and is as close to Read More …

Problem Detail: I have two questions regarding nullable nonterminals in a grammar. Often a simple algorithm is described to find nullable nonterminals: Basis: if $A rightarrow epsilon$ is a production, $A$ is nullable. Induction: if $A rightarrow X_1X_2ldots X_n$ is a Read More …