Problem Detail: By a vanilla Turing machine, I mean a Turing machine with one tape (no special input or output tapes). The problem is as follows: the tape is initially empty, other than a string of $n$ $1$s and $0$s terminated Read More …
Category: Uncategorized
Inequality caused by float inaccuracy
Problem Detail: At least in Java, if I write this code: float a = 1000.0F; float b = 0.00004F; float c = a + b + b; float d = b + b + a; boolean e = c == d; Read More …
NP-completeness and NP problems
Problem Detail: Suppose that someone found a polynomial algorithm for a NP-complete decision problem. Would this mean that we can modify the algorithm a bit and use it for solving the problems that are in NP, but not in NP-complete? Or Read More …
What is the exact relation between programming languages and Turing machines?
Problem Detail: I don’t know much about yacc, bison, flex or lex and please correct me if I’m wrong but a programming language is also a Turing machine and a Turing machine is defined as the tuple $(Q, Gamma, b, Sigma, Read More …
Why is CAN protocol preferred to be used in automotive application?
Problem Detail: Is it only because of the fact that it is asynchronous and can be used for long distance message transfer. An example of where other protocols will fail would help. Thanks. Asked By : Sirius Answered By : Pseudonym Historical reasons, Read More …
Graph 3-colorability is self-reducible
Problem Detail: I am interested in self-reducibility of Graph 3-Coloralibity problem. Definition of Graph 3-Coloralibity problem. Given an undirected graph $G$ does there exists a way to color the nodes red, green, and blue so that no adjacent nodes have the Read More …
Why does this sort algorithm work?
Problem Detail: The following O(n^2) sorting algorithm works but I can’t figure out why. array a // length n, indexed 0 to n-1 for ( i = 0; i < n; i++) for ( j = 0; j < n; j++) Read More …
Why is the consensus number for test-and-set, 2?
Problem Detail: According to Wikipedia, The test-and-set operation can solve the wait-free consensus problem for no more than two concurrent processes. Why can’t it solve the problem for more than two processes? Asked By : ben Answered By : Roy O. Just to Read More …
P, NP and specialised Turing Machines
Problem Detail: I’m sort of new, but very interested to the field of computing and complexity theory, and I want to clarify my understanding about how to class problems, and how strongly the problems relate to the machine being used to Read More …
Sorting as a linear program
Problem Detail: A surprising number of problems have fairly natural reductions to linear programming problems. See Chapter 7 of [1] for examples of network flows, bipartite matching, zero-sum games, shortest paths, a form of linear regression, and even circuit evaluation! Since Read More …
