Blog

Problem Detail: So based on the Chandy/Misra section in this Wikipedia article we’ve got 5 philosophers numbered P1-P5. Based on this quote: For every pair of philosophers contending for a resource, create a fork and give it to the philosopher with Read More …

Problem Detail: Given normally distributed integers with a mean of 0 and a standard deviation $sigma$ around 1000, how do I compress those numbers (almost) perfectly? Given the entropy of the Gaussian distribution, it should be possible to store any value Read More …

Problem Detail: Do “inductively” and “recursively” mean very similar? For example, if there is an algorithm that determines a n-dim vector by determine its first k+1 components based on its first k components having been determined, and is initialized with the Read More …

Problem Detail: I am trying to prove the NP-Hardness of the MAX-CUT problem. Other sources seem to reduce from the NAE-3SAT problem, however I have been trying to reduce from PARTITION because PARTITION and MAX-CUT are both in Karp’s list of Read More …

Problem Detail: In the ID3 algorithm for building a decision tree, you pick which attribute to branch off on by calculating the information gain. What happens if the calculated information gain is equal for two different attributes? Can you choose either Read More …

Problem Detail: I want an algorithm similar to Dijkstra or Bellman-Ford for finding the shortest path between two nodes in a directed graph, but with an additional constraint. The additional constraint is that there are $N$ sets of special edges with Read More …

Problem Detail: I have an array of real numbers, I want to partition them into k sets. In each set, I calculate the sum of squared error. Then, I add up all the sum of squared error for all the set. Read More …

Problem Detail: Is there an efficient algorithm which computes the (possibly approximately) shortest $n$-edge path between two points $A$ and $B$ in a weighted complete graph? Dijkstra won’t work because it will just give the trivial answer of $Ato B$. I’d Read More …

Problem Detail: Does there exist a recursive language $L$ whose cardinality is uncountable? I would like to have an explanation whether Turing Machine can encode uncountable languages and whether we can use this to reject the initial question. Asked By : revisingcomplexity Read More …

Problem Detail: Is there a language $L$ such that both $L$ and $L$’s complement are non turing recognizable languages, but there is a reduction between them? I couldn’t find one… Asked By : user3680924 Answered By : Tom van der Zanden Such a Read More …