Author: ignougroup

Problem Detail: I’m reading “Computer Science Made Simple” by V. Anton Spraul, and in the chapter about Graphics, he describes GIF files as follows: A GIF file uses lossless compression to store an image with a maximum of 256 different colors. Read More …

Problem Detail: I’m having a hard time understanding the actual proof of this proposition: $qquad mathsf{NP} subseteq mathsf{P}/log implies mathsf{P} = mathsf{NP}$ The sketch of the proof is on slides 6-8 of this PDF. So I let $L in mathsf{NP}$. That Read More …

Problem Detail: I’m reviewing for a computability test, and my professor has not provided solutions to his practice questions. I came up with a “solution” to this problem, but it really seems like my answer is wrong (since I call upon Read More …

Problem Detail: I have no idea how I managed to get this far in life without ever really grasping this but as it happens I’m still very confused on the concept of a hash function. I did some googling/wikipedia-ing, and here’s Read More …

Problem Detail: I was wondering if there is a polynomial time algorithm to test whether a DFA recognizes a star closed language ( which is if $A=A^*$). I think that yes, but I do not have an idea to do it. Read More …

Problem Detail: Given a whole number N.. Arrange 1 to N in a sequence such that no two numbers have their average sitting between them… Note – If N=20.. average of 19 and 2 = 10.5 is not a whole number Read More …

Problem Detail: I would like to use your help with the following problem: $L={⟨M⟩ ∣ L(M) mbox{ is context-free} }$. Show that $L notin RE cup CoRE$. I know that to prove $Lnotin RE$, it is enough to find a language Read More …

Problem Detail: Is the language $qquad L={ langle text{M} rangle ; | ; text{M is a Turing machine that decides some language} }$ a Turing-recognizable language? I think it’s not, as, even if I am able to tell somehow that a Read More …

Problem Detail: For problems like knapsack there is pseudopolynominaltime algorithm and it is np-complete. So we reduce every other problem in np in polytime to knapsack. But why don’t we have then a pseudopolynominaltime algorithm for all problems in np? Asked Read More …

Problem Detail: The related and interesting fields of Information Theory, Turing Computability, Kolmogorov Complexity and Algorithmic Information Theory, give definitions of algorithmically random numbers. An algorithmically random number is a number (in some encoding, usually binary) for which the shortest program Read More …