Problem Detail: I thought the answer would be 32 for remainder $0,1,2,dots, 31$. But answer given as $6$. and explanation is given as if the number is $2^n$ then number of states required would be $n+1$. Asked By : Vikrant Answered By : David Read More …
Category: Uncategorized
[Solved]: Understanding proof for Busy Beaver being uncomputable
Problem Detail: I found this proof on http://jeremykun.com/2012/02/08/busy-beavers-and-the-quest-for-big-numbers/ and have highlighted the part I don’t understand in bold. (BB(n) is defined as the number of steps made by n-state Busy Beavers.) Theorem: BB(n) is uncomputable. That is, there is no Turing Read More …
[Solved]: number of subsets where GCD equals to X
Problem Detail: The original statement for this problem can be found here This is a question from IEEExtream 2014. There is an array of integers given. Input is X, so output is the number of subsets where there GCD equals to Read More …
[Solved]: XOR-like behavior in flow networks
Problem Detail: XOR is not the correct name, but I am looking for some kind of exclusive behavior. I am currently solving a set of different (assignment) problems by modeling flow networks and running a min-cost-max-flow algorithm. Flow networks are quite Read More …
[Solved]: Matrix Max in less than O(n)
Problem Detail: I am attempting to find the maximum value in a matrix (or 2d array) and want to find it in less than O(n) time. The easiest way, which results in O(n) run time, is an element wise search. If Read More …
[Solved]: If L1 ∪ L2 and L1 are regular, is L2 also regular?
Problem Detail: This is a problem in a theory of computation book that’s stumping me: Suppose that we know that $L_1 ∪ L_2$ and $L_1$ are regular. Can we conclude that $L_2$ is regular? Explain. At first, I thought I could Read More …
[Solved]: What is the possible number of states in the DFA of intersection of two given FA?
Problem Detail: Consider a DFA over $a,b$ accepting all strings having number of $a$ ‘s divible by 6 and number of $b$ ‘s divisble by 8. What is the minimum number of states in the resultant DFA ? This problem Read More …
[Solved]: What is a forwarding pointer?
Problem Detail: I heard this terminology used today and haven’t come across it before, could someone please explain? Are there any other terms/names that describe this concept? Asked By : jcm Answered By : babou “Forwarding pointer” is the name of a technique Read More …
[Solved]: Computer science for programmers
Problem Detail: I’m a self-taught programmer and have been coding for 8 years. Due to this experience, I’m already very familiar with the principles of programming (such as if-statements, classes, polymorphism, etc.). However, I never learned “computer science,” only programming. What Read More …
[Solved]: Defining a “repeat until”-construct in Denotational semantics
Problem Detail: My Problem is: to define a “repeat until”-construct in terms of Denotational semantics. I made an attempt and now i need to know if i made it right. The Conditions are: i used the language “While” as specified in Read More …
