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Problem Detail: I am having trouble with a past exam paper. I have to design a Turing Machine to do the following, but I don’t really know where to start with this question. Any help would be very much appreciated. Design Read More …
Problem Detail: While I was solving a programming competition question, I came across a technique advertised as suitable for the solution. A so called Fenwick tree (a.k.a binary indexed tree) was at the heart of this technique. So in an effort Read More …
Problem Detail: I am a little confused which of the two laws above i should use: Suppose I have a computer program that can be parallelized by 70%. 30% cannot be parallelized. Every single data (100% of data) will pass the Read More …
Problem Detail: I have to write a regular expression that accepts any odd binary number not preceded by a 0. the best I can come up with is $1(0cup1)^*1$, but that doesn’t match just 1. The best it matches is 11. Read More …
Problem Detail: I was trying to solve this problem on SPOJ: Given a sequence of $n$ numbers $a_1, a_2, ldots, a_n$ and a number of $d$-queries. A $d$-query is a pair $(i, j)$, $(1 leq i leq j leq n)$. For Read More …
Problem Detail: For a given propositional formula f in DNF, one can decide in polynomial time, if the formula is satisfiable: Just walk through all subformulas (l_1 and … and l_k) and check, wheter it has NO complementary pair of literals. Read More …
Problem Detail: According to this chart, DCFLs are closed under reversal. However, I am not convinced as the intuitive proof (reversing the arrows of the controlling finite state machine and switching the pushes and pops) for this seems to depend on Read More …
Problem Detail: Someone I know is planning on implementing a text editor in the near future, which prompted me to think about what kind of data structures are fast for a text editor. The most used structures are apparently ropes or Read More …
Problem Detail: How are asymptotical time complexities calculated for recursive algorithms? Recursive algorithms call themselves and therefore take up more space compared to non-recursive algorithms. But are they better taking time complexity into account? If they are better than non-recursive algorithms, Read More …
Problem Detail: My teacher asked me to convert the regular expression $(a | b)^*$ to an NFA using Thompson’s algorithm – well, I’m well aware of how this algorithm works, but since I’m not good at memorising details, I produced a Read More …
