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Problem Detail: I am to prove that monotone boolean formula satisfiability checking when at most k variables are set to 1 is an NP-Complete problem. Proving that it is in NP is easy, but I’m having difficulty showing that it is Read More …

Problem Detail: some questions have been popping up recently on ambiguity in CFLs/CFGs which can have subtleties (eg languages vs grammars & ambiguity vs inherent ambiguity). wikipedia states: Many [context free?] languages admit both ambiguous and unambiguous grammars, while some languages Read More …

Problem Detail: I’ve written a recursive-descent parser generator, and I’m trying to classify it (call me a cowboy coder if you must). According to wikipedia, S → 0S0 | 1S1 | ε, which checks for an even-length palindrome, is a non-deterministic Read More …

Problem Detail: I’m learning how to convert NFAs to DFAs and I want to make sure I’m doing it right. Obviously, going back in the other direction isn’t a thing. Does anyone know of an algorithm to check that a DFA Read More …

Problem Detail: I’m having a hard time viewing Turing’s solution to the Halting Problem as a logician, rather than as an engineer. Here is my understanding of the Halting Problem: Let $M$ be the set of all Turing Machines. Let $i$ Read More …

Problem Detail: I am currently looking into Big O notation and computational complexity. Problem 1.1 in CLRS asks what seems a basic question, which is to get an intuition about how different algorithmic complexities grow with the size of the input. Read More …

Problem Detail: I was having a heated debate with a friend of mine (who considers me an idiot, mind you) and we were arguing about whether a compiler has an index, or coefficient, that judges how poorly code is written. Things Read More …

Problem Detail: How to prove that BFS directed-graph traversal algorithm terminates? (I copy the pseudocode from here) Input: A graph G and a root v of G. procedure BFS(G,v): create a queue Q enqueue v onto Q mark v while Q Read More …