Problem Detail: I have a $n times m$ rectangular grid of cells, and a set $R$ of rectangles within this grid. Each rectangle is a subset of the cells. (Alternatively, you can think of them as axis-aligned rectangles where each of Read More …
Category: Uncategorized
[Solved]: Why is pure literal elimination absent in DPLL-based algorithms like Chaff?
Problem Detail: I’m looking into various SAT-solvers and trying to understand how they work and why they are designed in certain ways. (But I’m not in a university at the moment and I do not know anyone who is a professor. Read More …
[Solved]: What is a Universal Turing machine?
Problem Detail: Could a Universal Turing machine be set up so that it is able to ‘reprogram’ itself to ‘behave’ like any specific Turing machine without using some ‘outside’ source of info to cause it to do this? Asked By : 201044 Read More …
[Solved]: How is clock syncing implemented?
Problem Detail: I’m looking for an explanation or reference on the implementation of computer clock. To keep the question at the level of logical abstractions: say, we put together some combinational and sequential logic from basic gates. The role of the Read More …
[Solved]: Is Deciding Decidability Decidable?
Problem Detail: I am wondering if deciding the decidability of problem is a decidable problem. I am guessing not, but after initial searches I cannot find any literature on this problem. Asked By : sync Answered By : Rick Decker Major edit of Read More …
[Solved]: Big O running time for this algorithm?
Problem Detail: Here’s the code for the algorithm: Foo(n) lcm = 1 for i = 2 to n lcm = lcm*i/Euclid(lcm,i) return lcm The running time of Euclid$(a, b)$ is given as $O(log(min(a, b)))$ So the running time of the for Read More …
[Solved]: Big-O complexity when c is a tiny fraction
Problem Detail: Finding Big-O is pretty straightforward for an algorithm where $f(n)$ is $$f(n) = 3n^4 + 6n^3 + 10n^2 + 5n + 4$$ The lower powers of $n$ simply fall off because in the long run $3n^4$ outpaces all of Read More …
[Solved]: How can you bound the error of an approximation without knowing the optimal solution?
Problem Detail: I been looking at this site and it says that people found solutions for TSP tours that are just 0.031% higher than the optimal tour is. Without finding the optimal tour how does they know what length it is Read More …
[Solved]: termination of two concurrent threads with shared variables
Problem Detail: We’re in a shared memory concurrency model where all reads and writes to integer variables are atomic. do: $S_1$ in parallel with: $S_2$ means to execute $S_1$ and $S_2$ in separate threads, concurrently. atomically($E$) means to evaluate $E$ Read More …
[Solved]: Is $A={ w in {a,b,c}^* mid #_a(w)+ 2#_b(w) = 3#_c(w)}$ a CFG?
Problem Detail: I wonder whether the following language is a context free language: $$A = {w in {a,b,c}^* mid #_a(w) + 2#_b(w) = 3#c(w)}$$ where $#_x(w)$ is the number of occurrences of $x$ in $w$. I can’t find any word that Read More …
