Problem Detail: Given an integer $n$ and set of triplets of distinct integers $$S subseteq {(i, j, k) mid 1le i,j,k le n, i neq j, j neq k, i neq k},$$ find an algorithm which either finds a permutation $pi$ Read More …
Category: Uncategorized
[Solved]: How can I compute the average weight of an undirected graph?
Problem Detail: Given a weighted, undirected graph $G = (V,E)$, how can I compute the average weight of edges? It seems an easy problem (divide the total weight to the number of edges!) but I couldn’t manage to find the sum Read More …
[Solved]: ILP and number of variables in constraints
Problem Detail: This question is about the time impact of the length (i.e. number of variables) of the constraints in an Integer Linear Programming formulation. Most people try to reach the minimum number of constraints/variables, but I couldn’t find anything that Read More …
[Solved]: Is a secondary TM sufficient to detect all loops?
Problem Detail: Procedure: Start a secondary TM in parallel with the first, but have the second perform exactly 1 step each 2 steps the first TM performs (i.e. it runs at half speed). If the second machine ever reaches the same Read More …
[Solved]: Lamport Timestamps: When to Update Counters
Problem Detail: In the timepiece (excuse the pun) that is Time, Clocks and the Ordering of Events, Lamport describes the logical clock algorithm as the following: Each process $Pi$ increments $Ci$ between any two successive events. If event a is the Read More …
[Solved]: Can an artificial neural network convert from cartesian coordinates to polar coordinates?
Problem Detail: Given cartesian coordinates $x$ and $y$ as input, can a neural network output $r$ and $theta$, the equivalent polar coordinates? This would seem to require an approximation of the pythagorean theorem (which requires approximations of $x^2$ and $sqrt{x}$) and Read More …
[Solved]: Bidirectional Dijkstra vs Dijkstra
Problem Detail: Are there any kind of graphs where Bidirectional Dijkstra would expand more than Dijkstra? I tried to come up with an argument like this: Let node $n$ be expanded by Bidirectional Dijkstra. Now there are two possibilites: Node $n$ Read More …
[Solved]: Does every infinite recursive language contain an infinite regular subset?
Problem Detail: My intuition is telling me that this is not the case. But I am having trouble formulating a proof for this.How do I prove it ? Asked By : user3714205 Answered By : babou Take the language $L= {a^{2^p}mid pgeq 1}$. Read More …
[Solved]: Terminology for a graph with ports on its nodes
Problem Detail: A Graph is a well-defined concept in mathematics, computer science and engineering disciplines that depend on them. However, oftentimes a practical implementation of a (directed) graph in a certain domain or application requires that edges don’t merely connect vertices, Read More …
[Solved]: purpose of supercomputers
Problem Detail: Last fall I went on a tour of the Blue Waters supercomputer at the University of Illinois. I asked whether anyone ever used the entire computer. I was told that it was always working on multiple projects. That made Read More …