0
votes
0answers
5 views

What does undecidable problem means in context of a modern programming language?

Imagine following python code x = raw_input() print(x); Does the problem of undecidability means that there can be possibly an input to this program such that ...
0
votes
0answers
33 views

Transforming a simple graph into a grid graph polynomial time algorithm

I was wondering whether there is a polynomial time algorithm for transforming a simple graph into a grid graph. It seems likely enough that I can construct my own transformation but if there is ...
-1
votes
0answers
32 views

Support tortoise svn application [on hold]

Am currently working on developing an desktop application we could use at our startup to function along side the current repository tortoise svn and also monitor and track developer activity ( ...
6
votes
1answer
95 views

Are EXPSPACE-complete problems rare?

I am currently trying to find EXPSPACE-complete problems (mainly to find inspiration for a reduction), and I am surprised by the small number of results coming up. So far, I found these, and I have ...
2
votes
1answer
24 views

Definition of Projection Measure in the characterization of strong approximation Resistance in a paper by Khot et al

I'm reading a paper about Constraint Satisfaction Problems, specifically "A Characterization of Strong Approximation Resistance", Subhash Khot, Madhur Tulsiani, Pratik Worah (ECCC TR13-075). The ...
0
votes
0answers
25 views

Testing - Correcting Pairs in PCPs

The BLR linearity test and the low degree test are two common tools in PCPs. By my understanding these tests ensure bounds such that (self-) correctors can be applied. I have two questions regarding ...
0
votes
0answers
16 views

Minimizing a general submodular pseudo boolean function

Are there algorithms that minimize a general submodular pseudo boolean function (PBF) without first transforming it to a quadratic pseudo boolean function (QPBF)?
17
votes
11answers
3k views

Most memorable CS paper titles

Following a fruitful question in MO, I thought it would be worthwhile to discuss some notable paper names in CS. It is quite clear that most of us might be attracted to read (or at least glance at) a ...
-3
votes
0answers
25 views

Difference between parallel and concurrent buffering?

In double buffering there are two terms Concurrent buffering. Parallel buffering. What is the difference between them, answer with example will be appreciated. Are they both in use now a days ? ...
-1
votes
0answers
59 views

Necessity of a Turing machine for a given problem in order to reduce it to another

I found it surprising that a certain type of reduction hasn't been flagged anywhere (except in Cook's original 1971 proof). Yes, there are Cook reductions (also known as Turing reduction), and the ...
7
votes
1answer
74 views

Randomized identity-testing for high degree polynomials?

Let $f$ be an $n$-variate polynomial given as an arithmetic circuit of size poly$(n)$, and let $p = 2^{\Omega(n)}$ be a prime. Can you test if $f$ is identically zero over $\mathbb{Z}_p$, with time ...
-2
votes
0answers
33 views

Aggregated Analysis [on hold]

The answer is .................................. I am trying to study the answer but I have couple of confusions. how did they come with (n-1/2) / (1-1/2) in the 3rd line of the answer. What ...
-1
votes
0answers
32 views

How prevalent are traffic control algorithms?

Can anyone point me to some algorithms that specialize in traffic control and prevention? I am always wondering if traffic lights optimize for specific conditions.
2
votes
1answer
221 views

Complexity lower bound of finding the factorial of a number

I was wondering about the complexity of the factorial of a number mostly because this problem is not referenced in the complexity books I have read. Two similar problems, Matrix Multiplication and ...
-2
votes
0answers
50 views

need help with java, please anwser :) I have been using bluej [on hold]

Implement a Book class for a book store as described: A Book has a title, cost, and number in stock. Set the title and cost to values passed to the constructor. Create a “get method” for each ...
0
votes
0answers
78 views

Simple explanation of the O(n log n) algorithm for matrix chain multiplication

I've seen references to papers that talk of an algorithm that is able to compute the optimal order for multiplying matrices to reduce the number of operations (matrix chain multiplication), but does ...
-3
votes
0answers
25 views

three address code for matrix multiplication

Can somebody please give me the 3 address code for the following matrix multiplication: for (i=1 to n) do for (j=1 to n) do c[i,j]=0; for(i=1 to n) do for(j=1 to n) do for (k=1 to n) do ...
-3
votes
0answers
19 views

N input network sorting comparators [on hold]

Prove that an n-input sorting network must contain at least one comparator between the ith and (i + 1)st lines for all i = 1, 2, . . . , n − 1. Can anyon help me to solve this problem ?! Thanks in ...
2
votes
1answer
160 views

Ackermann Function Time Complexity

Are there any known problems that have an Ackermann function time complexity lower bound?
2
votes
0answers
52 views

Literature for representation for boolean functions

What is the standard literary reading to understand: $1)$ polynomial(including minimal) representation of boolean functions? $2)$ polynomial(including minimal) approximation of boolean functions? ...
0
votes
1answer
43 views

Can we design our own `if` clause in Normal Order evaluation

I have been reading SICP and have been thinking over a thing for quite some time related to evaluation using Substitution with ...
0
votes
0answers
52 views

Best Hamiltonian Cycle Problem solver

What is the best Hamiltonian Cycle Problem (HCP) solvers available in the market? Googling so far shows that there is one created by Flinders University that can solve at most 5000 node instances. I ...
3
votes
1answer
84 views

Gap in degree of representations of candidate boolean functions

Let $x_1,x_2,\dots x_n$ be literals. Let $P(x_1,x_2,\dots,x_n)$ be one of the following Boolean function: $0)$ Equality function - $Eq_k^n(x)=1\iff x_1+\dots+x_n= k$ $1)$ Threshold function - ...
0
votes
1answer
31 views

Safety property as closed set [on hold]

In the paper "the existence of refinement mappings", the formal definition of safety property is defined as closed set which is based on the definition of closed set: $\sigma|_m$ denote the prefix of ...
1
vote
0answers
38 views

Is the bitonic sort algorithm stable?

I was wondering, is the bitonic sort algorithm stable? I searched the original paper, wikipedia and some tutorials, could not find it. It seems to me that it should be, as it is composed of merge / ...
-3
votes
0answers
47 views

how to create general star from spanning tree [on hold]

i had read a paper "Approximation algorithms for the shortest total path length spanning tree problem" .I am not getting what's a star and general star.can you explain with an example ...
0
votes
0answers
82 views

Approximate Hard Problem

The Unique Game is easy to solve for exact solutions, but becomes extremely difficult for approximate solutions, with no exact solution available. It is quite against of our intuition. As it is known, ...
-2
votes
0answers
40 views

Determine if subgraph is spanning tree [closed]

I am looking for algorithm that allow me to determine whether given subgraph is spanning tree or not.
1
vote
0answers
28 views

NC algorithm for rank of skinny matrix

Suppose I want to find the rank of an $m \times n$ matrix $A$ over $GF(2)$, where $m \ll n$. The algorithms for rank in the literature seem to be focused on the case when $m = n$, giving a time ...
6
votes
2answers
340 views

Are there problems for which divide-and-conquer / recursion is provably useless?

When we try to construct an algorithm for a new problem, divide-and-conquer (using recursion) is one of the first approaches that we try. But in some cases, this approach seems fruitless as the ...
3
votes
0answers
104 views

Can we decide Red-blue cut problem in polynomial time?

Given a directed graph whose arcs are coloured red and blue and integers $r$ and $b$, can we decide in polynomial time whether the digraph has a cut with at most $r$ red arcs and at most $b$ blue ...
1
vote
0answers
56 views

Candidate Boolean Function with efficient rational representation compared to polynomial representation

Let $x_1,x_2,\dots x_n$ be literals. Let $P(x_1,x_2,\dots,x_n)$ be a boolean function. Let $d$ be the smallest degree of $f(x_1,x_2,\dots,x_n)\in \mathbb R[x_1,x_2,\dots,x_n]$ that represents ...
-5
votes
0answers
35 views

Will subset construction always result in a DFA? [closed]

I understand how converting an NFA to a DFA works, but I don't understand how we are GUARANTEED to get a DFA from subset (powerset) construction. For some reason, I think there is some NFA that ...
6
votes
0answers
43 views

Diameter of Cayley graphs of subgroups of $S_n$ without inverses

Babai and Seress proved that given a subgroup $G \leq S_n$ and a generating set $S$ of $G$, any permutation in $G$ can be written as a product of generators and their inverses of length ...
-1
votes
0answers
23 views

Find all the Cycle Bases in a Undirected Graph

How to find all the Cycle Bases in a Undirected Graph For example, given the graph: 0 --- 1 | | \ | | \ 4 --- 3 - 2 the algorithm should return 1-2-3 ...
1
vote
1answer
61 views

Rational function for Parity function

Let $x_1,x_2,\dots x_n$ be literals. Let $P(x_1,x_2,\dots,x_n)$ be the parity function. What is the smallest degree of $f(x_1,x_2,\dots,x_n)\in \mathbb R[x_1,x_2,\dots,x_n]$ that represents ...
-1
votes
0answers
41 views

Edge-based NP-hard problems for reduction

I have a problem formulation where the input is a undirected graph $G=(V,E)$, and the task is to add a set of new edges $F \subseteq V\times V \setminus E$ to $E$, but no node $v\in V$ receives more ...
0
votes
1answer
34 views

Reference request: Classical analog of quantum threshold theorem

For quantum circuits, once the gate error is below a threshold, the error probability of an entire computation can be driven exponentially small with polylog costs in time and space: ...
-1
votes
0answers
28 views

Is evolution by natural selection the most efficient form of self organization?

This question crosses a number of different categories, so I didn't know where to put it. Quite simply, if any system is able to undergo self-organization with initial inputs, and left to evole a near ...
5
votes
0answers
58 views

Efficient Reduction from Min Cut to st-Min Cut

I am aware that many known algorithms for min cut problem is not by reducing the problem to $st$-min cut. But the question of efficient reduction from min cut to $st$-min cut is still interesting to ...
0
votes
0answers
25 views

What is the resolution of the apparent contradiction in the Practical Byzantine Fault Tolerance paper?

This question refers to the paper by Miguel Castro and Barbara Liskov. On Page 4, the fourth paragraph of 4.2, it says "the primary... multicasts a pre-prepare message with m piggybacked to all the ...
4
votes
1answer
34 views

How to estimate the probability of distribution of a variable in a Constraint Satisfication Problem

Consider that we have a state space of n random variables, for simplicity, the variable value can be 0 or 1. Each variable has its probability distribution when it is not constrained, also for ...
9
votes
1answer
130 views

Does ${\bf AC^0PAD} = {\bf PPAD}$?

What happens if we define ${\bf PPAD}$ such that instead of a polytime Turing-machine/polysize circuit, a logspace Turing-machine or an ${\bf AC^0}$ circuit encodes the problem? Recently giving ...
2
votes
1answer
83 views

Automata and a kind of pumping lemma on state transition function

We encountered this question as an exercise in a Büchi automata book a couple of decades ago, and back then gave a few tries thinking that it should be easy. But haven't seen a solution. My ...
1
vote
0answers
42 views

Dynamic Multithreading Analysis of Cache Oblivious Matrix Multiplication

I am reading the paper of Frigo et. al., The Cache Complexity of Multithreaded Cache Oblivious Algorithms, 2007. They present an algorithm to multiply two $n \times n$ matrices. This algorithm is a ...
1
vote
1answer
113 views

NP-hardness of minimizing sum of weighted product

Consider a total of $d$ items, $\{I_1,I_2,\cdots,I_d\}$, each having a weight $w_i$ (a positive integer), and a total of $m$ bins, $\{B_1,B_2,\cdots,B_m\}$. We would like to distribute the items into ...
-6
votes
0answers
32 views

NP-hardness of n queens problem [closed]

i have following questions 1> is this statemnt true or false: "If we could solve an NP-hard problem in polynomial time, this would prove P = NP." 2>is n queens problen np hard or just np??? 3> iam ...
-4
votes
0answers
31 views

Oracle reduction to 3SAT [on hold]

Show that there is an oracle A and a language L\in NP^A (NP TM with access to oracle A) such that L is not polynomial time reducible to 3SAT even when the machine computing the reduction is allowed ...
1
vote
1answer
53 views

Concurrent transactions satisfying “serializability” but not “snapshot isolation”

In [Lin et al@TODS'2009] (Page 5), a history of concurrent transactions satisfying "serializability" ($\textrm{SR}$) but not "snapshot isolation" ($\textrm{SI}$) is given as follows: $H_{example}: ...
9
votes
2answers
392 views

How can I find the second cheapest spanning tree?

The classic Mininum Spanning Tree (MST) algorithms can be modified to find the Maximum Spanning Tree instead. Can an algorithm such as Kruskal's be modified to return a spanning tree that is strictly ...

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