Problem Detail: In my computer organization class I have been given a series of problems. One I’m stuck on currently is below: Assume that $X$ consists of 4 bits, $x_3 x_2 x_1 x_0$, and $Y$ consists of 4 bits, $y_3 y_2 Read More …
Category: Uncategorized
[Solved]: Can the human brain be considered Turing complete?
Problem Detail: I’m not a student in computer science, but from what I understand from the Wikipedia article on the topic, a programming language is Turing complete if it can emulate another Turing complete language’s algorithm. Now if we consider that Read More …
[Solved]: Is detecting “doubly” arithmetic progressions 3SUM-hard?
Problem Detail: This is inspired by an interview question. We are given an array of integers $a_1, dots, a_n$ and have to determine if there are distinct $i lt j lt k$ such that $a_k – a_j = a_j – a_i$ Read More …
[Solved]: Acquiring the necessary background for research
Problem Detail: I’m starting my mater’s thesis in computer science. I’m interested in computational Origami (algorithms mainly); I’ve read a little about the subject and I’m worried because I lack some of the knowledge that I think is necessary to do Read More …
[Solved]: Common Algorithms without Asymptotically Tight Bounds
Problem Detail: I can think of functions such as $n^2 sin^2 n$ that don’t have asymptotically tight bounds, but are there actually common algorithms in computer science that don’t have asymptotically tight bounds on their worst case running times? Asked By Read More …
[Solved]: If all infinite r.e. languages have an infinite recursive subset, then do co-r.e. languages not have such subsets?
Problem Detail: If all infinite r.e. languages have an infinite recursive subset, then can we logically take co-r.e. languages to not have such subsets by complemence? Asked By : user2896468 Answered By : Yuval Filmus In one word: no. It doesn’t follow logically. Read More …
[Solved]: Floating point rounding
Problem Detail: Can an IEEE-754 floating point number < 1 (i.e. generated with a random number generator which generates a number >= 0.0 and < 1.0) ever be multiplied by some integer (in floating point form) to get a number equal Read More …
[Solved]: Is this variant of ATM decidable?
Problem Detail: Ok so I understand how $mathrm{ATM} = {langle M,w rangle mid text{$M$ is a TM and $M$ accepts $w$}}$ is undecidable. Is this because $w$ is a variable? What if the parameter is fixed? Consider $mathrm{BTM} = {langle M,w Read More …
[Solved]: Calculating cache memory based on LRU algorithm
Problem Detail: Assuming i have 4 blocks of cache memory, Using the LRU (Least Recently Used) replacement algorithm on this following sequence of access to memory blocks: 1 2 3 4 5 2 5 4 1 5 2 3 : 1 Read More …
[Solved]: Are regular languages closed under sort (Parikh image)?
Problem Detail: Assume $L$ is a regular language over an ordered alphabet. Is the language built by taking every word in $L$ and sorting it always a regular language? Asked By : Andrew MacFie Answered By : Niel de Beaudrap No. Counterexample: assuming Read More …
