Author: ignougroup

Problem Detail: Are $log_{10}(x)$ and $log_{2}(x)$ in the same big-O class of functions? In other words, can one say that $log_{10}(x)=O(log x)$ and $log_{2}(x)=O(log x)$? Asked By : David Faux Answered By : Dave Clarke Yes. Because they differ only by a constant Read More …

Problem Detail: An independent set (IS) in a graph is a set $V’ subseteq V(G)$ of pairwise non-adjacent vertices. I am interested in the generalization $c$-IS where two nodes in $V’ subseteq V(G)$ need to have distance at least $c$ to Read More …

Problem Detail: I’m reviewing for finals and have a sample problem that I think I understand, but would like someone to bless my understanding or smack me and tell me why I’m wrong. I’m presented with a problem $Pi$ of unknown Read More …

Problem Detail: The basic idea is to have one or more symbol that clearly indicate the end. For example: Non-ambiguous: $ab^*c$ $(a|b)c$ $ab^+c$ $ab?c$ $a(b|c)$ $c(ab)^*ccc$ $acc^*d$ $abc|bcd$ Ambiguous: $abc^*$ $abc^+$ $abc?$ $acc^*$ or $ac^*c$ An alternative definition of a non-ambiguous Read More …

Problem Detail: Maybe I am missing something obvious, but can it be that P = co-NP $subsetneq$ NP or vice versa? My feeling is that there must be some theorem that rules out this possibility. Asked By : aelguindy Answered By : Boris Read More …

Problem Detail: EPAL, the language of even palindromes, is defined as the language generated by the following unambiguous context-free grammar: $S rightarrow a a$ $S rightarrow b b$ $S rightarrow a S a$ $S rightarrow b S b$ EPAL is the Read More …

Problem Detail: Is it not necessary to encode both the uppercase and lowercase letter while encoding a message with the move-to-front transform? From an old computer science course exam, the problem was to encode Matt_ate_the_mat starting with an empty list. Using Read More …

Problem Detail: I would like to learn more about Amdahl’s Law and other similar topics. In what branch of computer science would one place Amdahl’s law? Could someone point me to a textbook or further reading (aside from Wikipedia or other Read More …