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I have an algorithmic problem.
I have a set of different polygons in the 2D space. Each polygon is represented according to its vertex representation (x and y coordinates) and may contain up to N different vertices.
Assuming I have a set of N polygons, then for a new polygon k, how do I determine whether or not k ove... |
For my CS degree I have had most of the "standard" mathematical background:
Calculus: differential, integral, complex numbers
Algebra: pretty much the concepts up until fields.
Number Theory: XGCD and related stuff, mostly for crypto.
Linear Algebra: up until eigenvectors/eigenvalues
Statistics: probabilities, testing... |
I am learning how to solve the time complexity for the recurrence relation
$$
T(n) = 2T(n - 1) + n^2\text{, where }T(1) = 1
$$
The solution notes that I should begin by considering the following sequence:
$$
\text{Define }T^k(n) = T^{k - 1}(n + 1) - T^{k - 1}(n) \\
\text{and let }T^{(0)}(n) = T(n)
$$
How is... |
Introduction
For a paper I need contracts, which are also referred to as Design by Contract (DbC)1, and conceptually go back to Hoare[2]. For my work I need to apply contracts to Java bytecode. The question is only about using contracts on Java bytecode, nothing more.
If you ask, why do you want to use contracts on Jav... |
I try to get a better understanding about Failure Detectors in the field of Distributed Computing.
Let consider the algorithm for reaching consensus with Perfect Failure Detector, it's named as Perfect FDAgreement in the textbook Distributed Algorithms by Nancy A. Lynch on the page 679. In addition, it can be found in ... |
Does the output of a parser have to be a tree or could it also be general graph?
Moreover, is there any existing language or a plausible one that uses general graphs representation instead of trees for their syntax?
|
Let's say I have a problem which depends on two variables, $m$ and $n$. I also have two algorithms for solving the problem. How do I decide which algorithm to use?
For example, say I have an array of unique numbers $A$, not necessarily sorted, and a second sorted array $B$. I want to create a third array $C$ which c... |
Can someone please point me towards a rigorous derivation of the energy function of a discrete Hopfield network. What I want, is the derivation must start out with the structure of the network and prove that the critical points of the dynamical system can be obtained by minimization of some function (possibly by constr... |
There is a famous Coordinated Attack Problem. Let define a simple message-passing system $S$ with requirements
Uniform Agreement: No two processes decide dierently.
Validity:
(a) If all processes start with 0, then no process decides 1.
(b) If all processes start with 1, and there are no failures, then no process de... |
I have a complete $n$-partite graph, where each partite set has $n$ vertices (yes it's also $n$), so the graph has $n^2$ vertices in total. My problem is to find a minimum weight $n$-clique in the graph. I would like to know whether the problem can be solved in polynomial time.
More details of the terms:
Complete $... |
Let $G$ be a $d$-regular expander graph. What is the electrical resistance of $G$? Is it a constant independent of the number of nodes $n$ once $d$ is large enough? If not, can we give matching upper and lower bounds in terms of $n,d$?
|
I recently learned how to implement merge-sort, using a standard recursive algorithm. Can the algorithm be implemented in a way that allows for a tail-recursive implementation? Can it be implemented in an iterative style?
In general how can a recursive algorithm converted into an iterative and tail-recursive algorithm?... |
From what I have come to understand, the best way to implement it is to use the suffix array $S$ of the string $w$ and its LCP-array (Longest Common Prefix) $L$.
The answer can be obtained by
$$ \sum_{i=1}^{|w|} \left( |S[i]| -L[i-1] \right).$$
What I don't get is how and why is this working?
I would be very grateful... |
I have a set $S$ of integers. I want to remove all elements of $S$ that are divisors of another element of $S$. In other words, I want to compute $T = \{y \in S : \forall d \in S . d \nmid y \}$.
How do I do this efficiently?
I can see how to do it in $\Theta(|S|^2)$ time, by examining all pairs of elements of $S$ an... |
I hope my question makes sense: Starting with the premise that the untyped $\lambda $ calculus is equivalent in power to a Turing machine, to what in a Turing machine does adding types to the $\lambda $ calculus correspond? Is there some kind of automaton analog to typing, whether static or dynamic?
|
We need to convert wireframe representations of 3D objects into a representation consisting of 6 orthogonal views each containing nested (non intersecting) closed contours, each having a Z (depth/height) value. We are only concerned with 3D shapes compatible with the target representation. Can someone at least point us... |
This question is from an exam preparation that I have to demonstrate to my teacher to show him that I understood the topic thoroughly .
Given a set $S$ of integers with $n$ elements, an integer $z$ and an integer $k \leq 2$, sketch an algorithm that checks whether there are $k$ elements in $S$ of which the product equa... |
I often interact with people who want to ask for an algorithm for a computational problem (or its complexity), but they don't express it in a rigorous way for us (computer scientists) to understand.
Referring them to books like CLRS is not helpful because the examples there usually have a quite straightforward way of s... |
I tried this problem from CLRS (Page 39, 2.3-4)
We can express insertion sort as a recursive procedure as follows. In order to sort A[1... n], we recursively sort A[1... n-1] and then insert A[n] into the sorted array A[1... n-1]. Write a recurrence for the running time of this recursive version of insertion sort.
Th... |
Is it common to have a different feature set for samples in the train set and in the test set?
My use case is text categorization: when training, I use the words as the features. But when testing, I want to add hypernyms.
For example, if the training set contained the sentence "I eat a fruit", and there is a test sente... |
According to wikipedia, every finite set is computable.
Definition: set $S \subset N$ is computable if there exists an algorithm which defines in finite time if a given number $n$ is in Set.
Question: what is wrong with this counter-example:
given some $TM$
$S \subset N$
Lets assume $S$ could contain only $0$, i.e., ... |
Given two graphs $G_{1}(E_{G1},V_{G1})$ and $G_{2}(E_{G2},V_{G2})$, with scalar weights on the vertices, I would like to find a subgraph $H_{1}$ of $G_{1}$ that best matches some subgraph $H_{2}$ of $G_{2}$. However, in most papers I've seen the weights are usually on the edges, $H_{1}$ is pre-specified and the matchi... |
So, it's fairly easy to prove that if $L \in DCFL$, then $L \Sigma^* \in DCFL$. Basically, you take the DPDA accepting $L$. You remove all transitions on final states, and then for each $a \in \Sigma$ and each final state $q$, you add a transition looping from $q$ to $q$ on $a$.
I'm using this in a paper, and I'd love ... |
Let's say I have a software that calculates integrals, formally if possible and if not, then it computes an approximation by taking a small $dt$. Of course if the integral is an unknown number, I wouldn't be interested in giving it a name. But if I calculate $\int_0^e\left(\frac{\pi}e+1\right)dt$, I'd like to get $\pi+... |
I've developed the following backtrack algorithm, and I'm trying to find out it time complexity.
A set of $K$ integers defines a set of modular distances between all pairs of them. In this
algorithm, I considered the inverse problem of reconstructing all integer sets which realize a given distance multiset. i.e. :
Inp... |
Let $G$ be a directed graph, and $H$ a subgraph of $G$ that contains all the vertices of $G$. (In other words, $H$ is obtained by deleting some of the edges of $G$, but not any of the vertices of $G$.)
A subgraph isomorphism $\varphi$ from $G$ to $H$ is a graph isomorphism from some subgraph of $G$ to $H$. In other wo... |
I wonder if there exists a game in which $\epsilon$ - Nash equilibrium leads to a much higher payoff than any other Nash equilibrium.
Show, for every $\epsilon$ > 0, a two player game where there is an $\epsilon$-Nash equilibrium in which both players have a much higher payoff then in any Nash equilibrium.
What is $\e... |
I'm using a SAT solver to encode a problem, and as part of the SAT instance, I have boolean variables $x_1,x_2,\dots,x_n$ where it is intended that exactly one of these should be true and the rest should be false. (I've sometimes seen this described as a "one-hot" encoding.)
I want to encode the constraint "exactly... |
This is a cross-post of this StackOverflow question, (I'm not aware of linking questions between StackExchange sites). You can ignore the part about programming.
I'm making a journey planner (or a general timetable application) for all the public transport in my country (bus/train/air).
The state of the project is at m... |
We have an array of integers $a[]$, with each $|a[i]| \leq 10^{6}$, $size(a)\leq10^{5}$, and $a[i]-a[i-1]\leq100$.
Then we define the term range as a subarray $[x,y]$ of the array $a[]$, $x \lt y$.
We need to find total number of ranges that satisfy the property that for two given ranges $([x_{1},y_{1}]$ and $[x_{2},y... |
Given an undirected simple graph $G$ and two nodes $s$ and $t$, the question asks for an algorithm to find the shortest simple cycle (no edge or vertex reuse) that contains the two. As far as I know, the problem is NP-complete if the two constraint were changed to arbitrary, but what if the number is given?
|
I think of an algorithm which computes the time complexity. It would be great if a code editor could compute the time complexity of the selected lines and even compare two pieces of codes in order to help developer to select one of them. I heard something related with halting problem but couldn't figure out.
|
Are there any CS problems, preferably open, that are related to music or musical theory somehow? I would think of problem with musical notation but also probabilities when randomizing according to a scale or a tonality or general what is considered harmony in frequencies and physics, electromagnetism and waveforms.
Ca... |
What are some examples of difficult decision problems that can be solved in polynomial time? I'm looking for problems for which the optimal algorithm is "slow", or problems for which the fastest known algorithm is "slow".
Here are two examples:
Recognition of perfect graphs. In their FOCS'03 paper [1] Cornuéjols, Liu ... |
The Question: You are given a singly-linked list with n nodes that you can only iterate through once at most. You are given additional space to store one node (i.e. a pointer to it). Devise an algorithm that can operate under these conditions, choose/select one node from the list such that the the probability of each ... |
I'm doing some research with NFAs, and I'm wondering there are algorithms which quasi-efficiently minimize them. I realize that this problem is $PSPACE$ hard, so I'm not looking for a polynomial time algorithm.
What I mean by this is an algorithm which may run in exponential time in the worst cases, but which uses some... |
I am not entirely sure if the title is the correct way to phrase what is occurring. There is a recurring process which I decided to attempt to model using production rules similar to those used in a context-free grammar.
The real world process is a production line. It takes 1 unit, after 2 weeks, produces 1 unit, after... |
Problem: How do we can generate some mathematical close form of the following sequence, which has following 256 entries:
1 7 7 7 7 9 9 9 7 9 9 9 7 9 9 9 7 11 11 11 11 13 13 13 11 13 13 13 11 13 13 13 7 11 11 11 11 13 13 13 11 13 13 13 11 13 13 13 7 11 ... |
I'm writing a program (using genetic algorithms) that finds sort-of-optimal scheduling plan for a factory.
The factory has several types of machines (say, locksmith, miller, welding)
There are few machines of each type. (say, 3 locksmiths, 2 millers, 3 welders)
There are several types of operations (some machines do m... |
I am very familiar with error correcting codes. However, it is not obvious how to apply them to adaptive streaming data. There also doesn't seem to be much literature on the problem.
The naive approach might be to take small codewords of data and use forward error correction until there is a statistically significant c... |
When should I call a definition recursive and when should I call it inductive?
I have read Carl Mummert's nice answer on MSE. So if I understand correctly we refer to definitions of objects like natural numbers, lists, trees, etc. as inductive whereas we refer to definitions of operations over objects like $+$ or $head... |
Assume that we have an operation $f$ such that
$$
f([a_0,\ldots, a_n])= [f(a_0),\ldots,f(a_n)]
$$
Do we say that $f$ distributes over lits or do we say it commutes with lists?
Which one is the correct way of expressing this property?
How about the following?
What do we say for the relation between $f$ and $\vec{a} = a... |
Given two sets of vertices $U$ (size $n$) and $V$ (size $m$), how many possibilities of set of edges $E$ exist that make the bipartite graph $G = (U, V, E)$ connected?
Obviously there are $2^{n m}$ different set of edges but many will be disconnected.
|
As I think of data structures I studied and dealt with, they are all optimized to retrieve/put a random element, to perform optimally based on unspoken assumption that each element has equal odds of being asked for (e.g. Red-Black trees).
By the nature of my program, I need to maintain an online dictionary of items th... |
Below is a well-known equation for generalized recurrence relation in a divide and conquer paradigm (as described in CLRS) --
$$T(n) = aT(n/b) + f(n), \quad \text{where} \quad a \gt 1 \text{ , } b \geq 1$$
If we consider a case for merge-sort, the relation will look like this --
$$T(n) = 2T(n/2) + \Theta(n) \qquad \qq... |
I just not sure does empty set have a context-free grammar in Chomsky normal form?
That is, for $B=\emptyset$, then a context-free grammar is $S \to S$, I think which doesn't have a Chomsky normal form. I am not sure. Can some one explain?
|
Given an array of integers. Find two disjoint contiguous sub-arrays such that the absolute difference between the sum of two sub-array is maximum.
The sub-arrays should not overlap and it can not be empty.
eg [2 -1 -2 1 -4 2 8]
ans (-1 -2 1 -4) (2 8)
diff = 16
Better than $\mathcal O(n^2)$ solution was expected.
|
Searching for a number in an array is said to have a runtime of O(n) because there may be cases where the number doesn't exist in the array. In such cases, you'd have to have gone through the entire array, which is O(n).
But how about in the case where we know the number definately exists in the array? Does the runtime... |
During my involvement in a course on dealing with NP-hard problems I have encountered the PCP theorem, stating
$\qquad\displaystyle \mathsf{NP} = \mathsf{PCP}(\log n, 1)$.
I understand the technical definition of a PCP verifier, so I know in principle what kind of algorithm has to exist for every NP problem: a randomi... |
This is somewhat related to another question I asked, but I feel it's different enough to warrant its own question.
I'm doing research where I'm trying to find the structure of complements of a certain class of finite languages. It's easy for me to get the minimal DFAs accepting these languages, but I'd like to examine... |
When calculating runtime dependence on the input, what calculations are considered? For instance, I think I learned that array indexing as well as assignment statements don't get counted, why is that?
|
These are 5 action descriptions with conditional effects:
Action(A, Precond:{X}, Effect:{when P : ~X), Z})
Action(B, Precond:{Y}, Effect:{when Z : ~P), ~Y,~Z,X})
Action(C, Precond:{~Z}, Effect:{when P : ~X), Y})
Action(D, Precond:{~X}, Effect:{when Q : X)})
Action(E, Precond:{Z}, Effect:{when Q : ~Z)})
What state wou... |
I have the notion of a social network which is robust against malicious attacks from the outside. My vision is a system that is structurally built up as a distributed network of equal servers that operate on the same data and offer the identical services. Users should all interact on the same network, independent of th... |
We are given an array $a[1 \ldots n]$ with all $a[i]>0$.
Now we need to find how many distinct sums can be formed from its subarrays (where a subarray is a contiguous range of the array, i.e., $a[j\ldots k]$ for some $j,k$, the sum is the sum of all of the elements of the subarray). For example, if $a=[1,2,1]$, then th... |
Is there an efficient algorithm which gives the minimum cost closed walk in an undirected graph, which visits all vertices?
Does this problem have a name? I tried to reduce this to similar problems (in particular the traveling salesman problem) to see if it was NP-hard, but was unsuccessful.
Here's an example:
Then a ... |
Given a set $S$ of $k$ numbers in $[0, N)$.
The task is to randomly generate numbers in the range $[0, N)$ such that none belongs to $S$.
Edit - Also given an API to generate random numbers between $[0, N)$. We have to use it to randomly generate numbers in the range $[0, N)$ such that none belongs to $S$.
I would als... |
There is a river which can be considered as an infinitely long straight line with width W.
There are A piles on the river, and B types of wooden disks are available.
The location of the $i$-th pile is $(X_i, Y_i)$.
The $i$-th type of wooden disks has radius $R_i$, and its price is $C_i$ per disk.
Disks can be placed on... |
I know that for executing a program, it should be copied to RAM. But the problem is whole of it may not be copied always.
Since the size of the RAM is limited, there is mechanism called virtual memory. If the addressed thing is not in memory, a page fault occurs and the data is copied to the RAM. My question is who ke... |
It's known that the complement of a DFA can be easily formed. That is, given a machine $M$, we can construct $M'$ such that $L(M') = \Sigma^* \setminus L(M)$.
Is it possible to construct such a complement for a non-deterministic finite automation (NFA)? To my knowledge, it isn't.
|
I am reading about dependent types theory in the Homotopy Type Theory online book.
In section 1.3 of the Type Theory chapter, it introduces the notion of hierarchy of Universes: $\mathcal{U}_0 : \mathcal{U}_1 : \mathcal{U}_2 : \cdots$, where
every universe $\mathcal{U}_i$ is an element of the next universe $\mathcal{... |
I am trying to understand interactive proof systems and tried the following problem as an exercise. We know that $PH \subseteq PSPACE$ and $IP=PSPACE$, so come up with (easy to understand) interactive proof systems for $PH$?
An interactive proof system for $NP$ is trivial, but I failed to get an interactive proof syste... |
We mostly write programme in high level language. So while studying I came across assembly language. So an assembler converts assembly language to machine language and a compiler does the same with high level language. I found assembly language has instructions like move r1 r3 , move a 5 etc. And it is rather hard to s... |
I have about $500000000$, $64$-bit integers, so these numbers are very large.
I want to sort them as quickly as possible. I have couple of questions:
What data structure do you suggest for storing this data?
What algorithm do you suggest for sorting these numbers?
I'm concerned about speed.
|
does $BPP\subseteq P^{NP}$ ? it seems reasonable but I don't know if there is a proof of this!could any one post a proof or any material that discusses the statement or something that look like this .
|
Recently I have had this question in one of my interviews.
You have 1 Million sorted integer, you have a value of $x$, compare each pair in this array and if the addition of two pair is less or equal to $x$ then increment the paircounter.
I have implemented this solution in C++ however I will write pseudocode here(I am... |
How can I solve $\mathcal{O}$-notations without using Java or any other programming language?
I only want to use pen and paper.
|
In Andrew W. Appel's book, Modern Compiler Implementation in ML, he says under chapter 17 that Computability theory shows that it will always be possible to invent new optimizing transformations and proceeds to prove that a fully optimizing compiler will solve the halting problem: A program Q that produces no output an... |
I am given an undirected tree $T$ in the usual graph theoretic sense. Given a vertex $v$ and an edge $(v,u)$ incident to $v$, I need to answer queries of the form return any leaf of $T$ that is reachable from $v$ with a path including $(u,v)$, and no other edges incident to $v$? More informally, the restriction is that... |
Suppose I want to write a classical software simulator of a quantum circuit with $N$ qubits. When it comes time to simulate the quantum Fourier transform I can evaluate all $2^N$ states to determine the probability amplitudes, and then perform a Fast-Fourier Transform on the probability amplitudes in time $o(N 2^N)$. ... |
If a school has an IP that's like 10.0.x.x, and a department in that school has it's own site that's an extension of the school's site, does that department's IP just change the last two numbers in the IP?
Does the school have to purchase extra domain space?
Could I have additional addresses established at my IP addre... |
I'm looking for a context-sensitive grammar that describes the following language:
$L = \{ ww \mid w ∈ \{a,b\}^{\ast}, |w| ≥ 1\}$ .
I've got problems with the fact that no rules such as $X \to \varepsilon$ are allowed and therefore I can't place any nonterminal indicating the "middle" of the word. Is there any trick t... |
I'm trying to find parameters $\omega, \alpha,$ and $\beta$ which maximize
$$
\sum_{i=1}^m{\left\{ -\ln(v_i) - \frac{r_i^2}{v_i} \right\}}
$$
where
$$
v_i = \omega + \alpha r_{i-1}^2 + \beta v_{i-1}^2
$$
Since numerical values for $r_i$ and $v_1$ are given my first thoughts were to use the normal equation
$$
\Theta =... |
I have many vectors in my database. They are in high dimensions such as:
$v_1$ : $\langle 23, 23, 1, 33, 103, 219, \dots \rangle$
$v_2$ : $\langle 92, 83, 1, 33, 239, 192, \dots \rangle$
...
I will use Hamming distance to calculate their difference: The
difference between $v_1$ and $v_2$ is $4$ because elements $3$
a... |
My problem. Given $n$, I want to count the number of valid multisets $S$. A multiset $S$ is valid if
The sum of the elements of $S$ is $n$, and
Every number from $1$ to $n$ can be expressed uniquely as a sum of some of the elements of $S$.
Example.
For example if $n=5$ then $\{1,1,1,1,1\}, \{1,2,2\}, \{1,1,3\}$ are ... |
I try to understand why fragmentation is a problem for NTFS and FAT but not when using inodes.
In all cases, files are not necessarily stored in a contiguous fashion so I don't see the problem for the former two.
So where is the crucial difference?
|
I'm trying to proove $NP$-membership for a problem from the following certificate.
I have $n$ sets of integers :
$$(S_i)_{i \in \{1,\dots,n\}}$$
Each set has a number $m_i$ of integers.
I make "combination" from those sets by taking at most one element in each set.
A "combination" has between $0$ and $n$ elements (assu... |
A question about Laplace's approximation:
In Laplace's method, we need to find the mode of a function and take second order Taylor's expansion. The first order term will vanish (since the gradient is zero at local optimum), and the second order term will be used to give a covariance of the gaussian. I am wondering if I... |
The global alignment problem can be generalized by setting the cost of some boundary gaps to 0.
Gaps at both end in both strings have 0 cost, then we get the semiglobal alignment.
Gaps are at the left end of the first string, and right end of second string have 0 cost, then we get overlap alignment.
If both boundary g... |
Specifically:
1) A direct-mapped cache with 4096 blocks/lines in which each block has 8 32-bit words. How many bits are needed for the tag and index fields, assuming a 32-bit address?
2) Same question as 1) but for fully associative cache?
Correct me if I'm wrong, is it:
tag bits = address bit length - exponent of ind... |
I'm currently working on my masters thesis, and it's about clustering on graphs. I'm working with an idea using ants to solve the problem. I'm currently working on the implementation and am wondering exactly how well to represent the edges of the graph.
Each edge is augmented with certain information such as its phero... |
I have a real function $f:\mathbb{{R}}^{d}\mapsto\mathbb{R}$, where
$d>1$. The question is how to compute the level set $A=\left\{ \theta:f\left(\theta\right)\geq a\right\} $.
I am a statistician knowing very few things about computer science.
I would appreciate very much if anyone could suggest some reference, methods... |
Given a linear system of the form:
$$\begin{array}{c}
x_r = a \quad x_j = b \\
c_1x_1 + c_2x_2 + \ldots + c_nx_n = N \\
x_1+x_2 + x_3 + \ldots + x_n = k\\
0 \le a,b,x_1,x_2,x_3...x_n \le 1\\
k \ge 0
\end{array}$$
How quickly can the feasibility of the system be checked? To clarify: $x_r,x_j$ are members of $x_1,x_2...x... |
I've constructed an algorithm that solves the 3SUM problem in $O(n\lg n) + \frac{n^2}{4}$ time. I'm new to algorithms and was wondering how good is my running time? Googling didn't help.
thanks..
|
Let there is a binary-string, $B$, of length $N$. The probability of occurrence of 0 and 1 in this binary-word is $p$ and $q$ , respectively. Each bit in the string is independent of any other bit.
There is an algorithm (divide and conquer) which finds the location of 1’s in a given binary-string, in Q # of steps (cos... |
I'm attepting to model a process flow where the transition to the next state is occasionally based on not only the input to the current state, but a prior state as well.
Below is an example graph descibring the process. The essence is: If both State Q1 and State Q3 recieve an input of one, after State 3, transition to ... |
The paragraph on V-opt heuristic TSP algorithms at this site mentions a very effective algorithm due to Lin-Kernigham-Johnson. That page says:
For many years Lin–Kernighan–Johnson had identified optimal solutions for all TSPs where an optimal solution was known and had identified the best known solutions for all othe... |
The problem is from CLRS 9.3-1:
In the algorithm SELECT, the input elements are divided into groups of
$5$. Argue that SELECT does not run in linear time if groups of $3$ are used.
If we do the "divide by $3$" technique, we will come up with this recurrence --
$$T(n) = \begin{cases}
\Theta(1) & \text{if $n \le K$}... |
Is $L = \{A^n B^n C^n \mid n \in \mathbb{N}\}$ a context-free language, e.g. $AAAABBBBCCCC \in L$
If so, what's that context-free grammar that produces it?
|
I am trying to solve the question 6.12 in Arora-Barak (Computational Complexity: A modern approach). The question asks you to show that the
$\mathsf{PATH}$ problem (decide whether a graph $G$ has a path from a given node $s$ to another given node $t$) which is complete for $\mathbf{NL}$ is also contained in $\mathbf{NC... |
For a language L we define:
$\qquad A(L) = \{ x \in L \mid \text{ no proper prefix of x is in L} \} $
Are regular / context free languages closed under this operation ?
For regular languages I thought about taking the DFA that accepts the language L and create a new NFA by making all accepting states sinks (so the on... |
I've written a recursive-descent parser generator, and I'm trying to classify it (call me a cowboy coder if you must). According to wikipedia, S → 0S0 | 1S1 | ε, which checks for an even-length palindrome, is a non-deterministic grammar. My parser generator can handle this grammar. Does that mean my parser is non-deter... |
I've been using Clojure for about 18 months. Recently, I've come across terms such as Monads, Continuations, et al which I'd like to learn about.
I could visit Wikipedia and read about these two topics, but I'm looking for a reference which also help me learn about related matters that I don't even know exist. Is there... |
I realize non-deterministic pushdown automata can be an improvement over deterministic ones as they can "choose" among several states and there are some context-free languages which cannot be accepted by a deterministic pushdown.
Still, I do not understand how exactly they "choose". For palindormes for example every so... |
Suppose that I have run maxflow algorithm on a graph G and, as a result, I have a set of edges with flow on them.
I would like to enumerate all possible sets of paths that comprise the maxflow.
That is, each set of paths will make the max flow.
But I suspect there could be multiple set of such paths.
|
(It might be useful to refer to page 9 of Multi-Armed Bandit Allocation Indices by Gittins, Glazebrook and Weber if you have it, because there explanation will be much better than mine.)
I'm trying to write a program that finds that optimal expected reward for a 2-armed Bernoulli bandit process where the first arm has ... |
I need to know if the following problem is $NP$-complete.
The data are as follows :
$n$, number of items
$\{s_{i}\}_{i \in \{1, \dots n\}}$, item sizes, sorted by ascending values.
$S$ knapsack capacity.
$T$ a lower bound on the value to be attained.
Now, for each $i \in \{1, \dots n\}, c_i = \log i $ is the value o... |
In other words, can a programming language be referentially transparent even if not everything is an expression?
And can you say that if in a programming language, everything is an expression, then it is referentially transparent?
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I've got the following theoretical problem which puzzles me a bit:
I can obtain a string of n bytes (as octets, one byte = one octet = eight bits) of random data. I need to preserve the randomness while reducing the base from 256 to x where x is below 256 (and not 0, 1, 2, 4, 8, 16, 32, 64 or 128).
As I want to preserv... |
Assume I have producer and consumer in a monitor.
The code of the consumer signals the producer and then does something else.
I know in a Hoare-style monitor, after signaling, the thread that is signaled wakes up and is is now schedule.
What about the other instructions in the consumer after the signal? When will the ... |
I'm trying to create simple tokenizer to transform following (only part shown) search expression to tokens
word1 near(1) word2
where word1, word2 are some words and near(1) is distance operator.
The question is how this expression should be tokenized.
I see two ways
1. <WORD, word1> <WORD, near> <LPAREN> <NUMBER,1> <... |
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