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Problem Detail: So I have this question to prove a statement: $O(n)subsetTheta(n)$… I don’t need to know how to prove it, just that in my mind this makes no sense and I think it should rather be that $Theta(n)subset O(n)$. My Read More …

Problem Detail: There is a well known definition of parsimonious reduction. The standard definition of parsimonious reduction is very intuitive. It simply means that the two problem have the same number of solutions, when on input of one of them we Read More …

Problem Detail: Can quantum computer become perfect chess player? Can it determine whether (when both players are perfect) win white or black? (or is it dead heat?) Asked By : porton Answered By : David Richerby I’ve already answered essentially this question, on Read More …

Problem Detail: In this paper (page 3 Theorem 1) the authors want to prove that their problem is NP-complete. Their method is as follows. Let their problem be known as $P$. They show that their problem can be written as a Read More …

Problem Detail: Let $G = (V,E)$ be a directed graph with a weight function $w$ such that there are no negative-weight cycles, and let $v in V$ be a vertex such that there is a path from $v$ to every other Read More …

Problem Detail: A deterministic finite automaton (DFA) is a state machine model capable of accepting all and only regular languages. DFAs can be (and usually are) defined in such a way that each state must provide some transition for all elements Read More …

Problem Detail: What I’m trying to do is generate Motzkin numbers mod a large number $10^{14} + 7$ (not prime), and it needs to compute the $n$th Motzkin number as fast as possible. From Wikipedia, the formula for the $n$th Motzkin Read More …

Problem Detail: I often see claims that modern functional strictly-typed languages are ‘safer’ than others. These statement mostly linked with type systems and their ability to explicitly express the following sources of pitfalls: Alternatives in function result. Maybe and Either datatypes Read More …

Problem Detail: Say I have some problem of $Oleft(n^kright)$ complexity. If I were to solve the problem on a computer $x$, it would take time $t$. Now I have a new computer $x’$, which has double the computing power of $x$. Read More …

Problem Detail: Using the Deterministic Finite Automaton (Q, Σ, Δ, q_0, F): Alphabet: Σ is {(0 0), (0 1), (1 0), (1 1)} Definition of Δ to strings recursively: Δ*(q, ε) = q for all q ∈ Q Δ*(q, xa) = Read More …