Problem Detail: I was wondering if anyone had any good references or book recommendations that cover abstract syntax trees (ASTs). Specifically, I am interested in the abstract syntax trees of different evaluation strategies (call by value vs. call by name) of Read More …
Author: ignougroup
[Solved]: How do we derive the runtime cost of Karatsuba’s algorithm?
Problem Detail: I’ve read the Wikipedia article explaining the complexity analysis of the Karatsuba algorithm, but I’m not fully grasping it. I seem to have gotten about 75% of the way to the solution on my own, but lack the last Read More …
[Solved]: Simple explanation of Simon’s Problem
Problem Detail: I just read the Wiki article for Simon’s Problem but I don’t fully understand it because I don’t follow the symbolic notation used to describe functions (I am not a computer scientist). Can someone just briefly explain it in Read More …
[Solved]: NP-complete problems not “obviously” in NP
Problem Detail: It occurred to many that in all the $textbf{NP}$-completeness proofs I’ve read (that I can remember), it’s always trivial to show that a problem is in $textbf{NP}$, and showing that it is $textbf{NP}$-hard is the… hard part. What $textbf{NP}$-complete Read More …
[Solved]: Is a stack machine with a forward read iterator Turing complete?
Problem Detail: It is well known that a machine with a single stack as only unlimited storage is not Turing complete, if it can only read from the top of the stack. I want a machine which is (slightly) more powerful Read More …
[Solved]: What is the difference between radix trees and Patricia tries?
Problem Detail: I am learning about radix trees (aka compressed tries) and Patricia tries, but I am finding conflicting information on whether or not they are actually the same. A radix tree can be obtained from a normal (uncompressed) trie by Read More …
[Solved]: Efficient algorithm for finding weakly connected components
Problem Detail: We recently studied Tarjan’s algorithm at school, which finds all strongly connected components of a given graph. I was curious however how one would find all weakly connected components (I had to search a bit to actually find the Read More …
[Solved]: How to convert PDA to CFG
Problem Detail: I learned how to convert context-free grammar to pushdown automata but how can I do the opposite? to convert PDA to CFG? For example: to write CFG for the automata My attempt: $S=A_{03}$ because $q_{color{blue}0}$ is the initial state Read More …
[Solved]: Show that if d(n) is O( f (n)) and e(n) is O(g(n)), then d(n)−e(n) is not necessarily O( f (n)−g(n))
Problem Detail: I have this question as an assignment in my Java Algorithms class, and i’m aware that d(n)+e(n) is the same as O(f(n)+g(n)). I dont know why the same doesnt apply to subtracting. Can someone help me? I’m lost.. Asked Read More …
[Solved]: What is “polynomial delay?”
Problem Detail: I am reading a paper and it uses the expression “polynomial delay” which I don’t understand. It is used in conjonction with the big O notation, which I’m familiar with. Here is a example sentence showing how it is Read More …
