ignougroup, Author at IgnouGroup

[Solved]: Automata that recognizes Kleene closure of permutations of three symbols

January 28, 2017March 27, 2017 ignougroup

Problem Detail: This is an automata theory homework question. I need to create DFA that meets the following criteria: Alphabet $Sigma = { a, b, c }$ Machine accepts empty string and strings of length that is a multiple of three, Read More …

[Solved]: Why does merge sort run in $O(n^2)$ time?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: I have been learning about Big O, Big Omega, and Big Theta. I have been reading many SO questions and answers to get a better understanding of the notations. From my understanding, it seems that Big O is the Read More …

[Solved]: Predicate Logic Notation: What does a “dot” mean?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: What does a dot (.) mean in predicates? $forall a in A. exists d in D. H(a,d)$ Especially, how is the above different to $ exists d in D. forall a in A. H(a,d)$ I’ve never seen this used Read More …

[Solved]: Is it possible to do Dependent Types in Typed Racket?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: Is it possible to use Dependent Types in the existing Typed Racket implementation? (ie do they exist in it?) Is it reasonably possible to implement a Dependent Types System using Typed Racket? Asked By : hawkeye Answered By : hawkeye Dependent Read More …

[Solved]: Proving the language $L= {0^n 1^m space | space m equiv 0 space mod space n, space n geq 2 }$ is not regular using the pumping lemma

January 28, 2017March 27, 2017 ignougroup

Problem Detail: I am trying to learn about applying the pumping lemma and I’m not really sure how to go about proving this language isn’t regular with the pumping lemma: $L= {0^n 1^m space | space m equiv 0 space mod Read More …

[Solved]: Constructing Tree (forest) from Ancestor function

January 28, 2017March 27, 2017 ignougroup

Problem Detail: Question: Suppose I have a set of male people, and a function isAncestor(person1,person2) that checks whether person1 is an ancestor of person2 in O(1) time. Eg, isAncestor(grandfather, grandson) would return true. What are some fast algorithms for constructing a Read More …

[Solved]: Can heuristic methods and machine learning approaches be considered alternate methods to solve NP-Complete problems?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: I was watching the videos from Skiena’s Computational Biology Lectures, which is also available at youtube. In those videos, the professor made a statement that, most of the problems posed to computer scientists by biologists were proved to be Read More …

[Solved]: What is the most efficient algorithm and data structure for maintaining connected component information on a dynamic graph?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: Say I have an undirected finite sparse graph, and need to be able to run the following queries efficiently: $IsConnected(N_1, N_2)$ – returns $T$ if there is a path between $N_1$ and $N_2$, otherwise $F$ $ConnectedNodes(N)$ – returns the Read More …

[Solved]: What is the use of finding minimum number of straight lines to cover a set of points?

January 28, 2017March 27, 2017 ignougroup

Problem Detail: There is that popular problem [1] [2] in the computer science that is finding minimum number of straight lines that covers a given set of points in 2D. Even though I have scanned many papers, none of them has Read More …

[Solved]: Equivalence of Turing Machines

January 28, 2017March 27, 2017 ignougroup

Problem Detail: Consider the following two arguments “For every non deterministic TM M1 there exists an equivalent deterministic machine M2 recognizing the same language.“ “Equivalence of two Turing Machines is undecidable” These two arguments seem a bit contradicting to me. What Read More …