Author: ignougroup

Problem Detail: I searched linear solver library and found out PETSc library which considered to be powerful and useful library. PETSc consists implementations of various iterative methods with preconditioners and sparse matrix storing methods. All methods are realized sequentially and in Read More …

Problem Detail: What’s the difference between a stream and a queue? They both have the concept of an ordered set of elements, but tend to have different implementations and a different vocabulary of ‘insert’/’extract’ (streams) vs. ‘enqueue’/’dequeue’ (queue). Are these interchangable? Read More …

Problem Detail: I want to establish that this is part of my homework for a course I am currently taking. I am looking for some assistance in proceeding, NOT AN ANSWER. This is the question in question: A 5-pointed-star in an Read More …

Problem Detail: $G=<V,E>$ is a directed graph. I need to write an efficient algorithm that finds a $v in V$ such that there exists a path $forall w in V$ $v rightarrow w$ ($v$ has a path to every other vertex), Read More …

Problem Detail:  Calculate the FOLLOW sets for all the non terminals: $S rightarrow bEx mid Db mid b mid F$ $D rightarrow EDc mid Y$ $E rightarrow dED mid dDY$ $Y rightarrow ab mid aDx mid varepsilon$ So I know Read More …

Problem Detail: A pseudo-polynomial time algorithm is an algorithm that has polynomial running time on input value (magnitude) but exponential running time on input size(number of bits). For example testing whether a number $n$ is prime or not, requires a loop Read More …

Problem Detail: In the set cover problem we want to find in the $mathbb{S} subset 2^mathbb{U}$ the subset ${s_i}_{1..k}$, such that $cup s_i = mathbb{U}$ for given $K$, where $k le K$. But how to reduce the set cover problem to Read More …

Problem Detail: Let G = (V,E) be a unit-capacity graph with n vertices and m edges. Let T denote all the spanning trees in G. If we run Karger’s algorithm, we will get a random spanning tree in T formed by Read More …

Problem Detail: The Problem: Let T be a tree constructed by Dijkstra’s algorithm in the process of solving the single source shortest-paths problem for a weighted connected graph G.    a. True of false: T is a spanning tree of G? Read More …

Problem Detail: If $A^2$ is regular, does it follow that $A$ is regular? My attempt on a proof: Yes, for contradiction assume that $A$ is not regular. Then $A^2 = A cdot A$. Since concatenation of two non-regular language is not Read More …