Problem Detail: I have multiples arrays. I’d like to enumerate all sets containing exactly one item from each array in a (pseudo-)random order, without explicitly building the array of all sets. Any solution, even with poor pseudo-randomization, is welcome. EDIT: Example Read More …
Category: Uncategorized
[Solved]: Brzozowski algebraic method for NFA
Problem Detail: Currently I have a graph (basically, a state graph) in Scala which is similar to an NFA some nodes have multiple in/outgoing edges single start state there might be multiple final states a state can contain self loops where Read More …
[Solved]: lambda calculus as a type theory
Problem Detail: From the Introduction section of Homotopy Type Theory book: Type theory was originally invented by Bertrand Russell … It was later developed as a rigorous formal system in its own right(under tha name “$lambda$-calculus”). Can anyone explain me this Read More …
[Solved]: Proving the security of Nisan-Wigderson pseudo-random number generator
Problem Detail: Let $cal{S}={S_i}_{1leq ileq n}$ be a partial $(m,k)$-design and $f: {0,1}^m to {0,1}$ be a Boolean function. The Nisan-Wigderson generator $G_f: {0,1}^l to {0,1}^n$ is defined as follows: $$G_f(x) = (f(x|_{S_1}) , ldots, f(x|_{S_n}) )$$ To compute the $i$th Read More …
[Solved]: How to represent circles in x-y coordinates
Problem Detail: I would like to be able to represent circles in x-y coordinates. Each circle contains an x and y coordinates and radius in double data type. My goal is to compare circles with each other whether they are partially Read More …
[Solved]: Is the type inference here really complicated?
Problem Detail: There’s a question on SO asking why in Java the right type doesn’t get picked in a concrete case. I know that Java can’t do it in such “complicated” cases, but I’m asking myself WHY? The (for simplicity slightly Read More …
[Solved]: Understanding Instruction Cycle?
Problem Detail: A basic instruction cycle consists of these 5 stages. Instruction Cycle IF – Instruction Fetch RD – Instruction Decode and Register Read EX – Execute MA – Memory Access WB – Write Back I understood the function of all Read More …
[Solved]: Supporting queries for finding how many intervals in a dynamic set of 1D intervals contain a given point
Problem Detail: You want to create a data structure that can store 1 dimensional intervals and also support the query for finding the total amount of intervals intersecting a given point. One solution would be for each query to scan through Read More …
[Solved]: How to prove that ε-loops are not necessary in PDAs?
Problem Detail: In the context of our investigation of heap automata, I would like to prove that a particular variant can not accept non-context-sensitive languages. As we have no equivalent grammar model, I need a proof that uses only automata; therefore, Read More …
[Solved]: Running time analysis of a segment tree
Problem Detail: Can someone provide an analysis of the update and query operations of a segment tree? I thought of a way which goes like this – At every node, we make at most two recursive calls on the left and Read More …