IgnouGroup Social Campus
Problem Detail: Point-Cover-Interval Problem: Given a set $mathcal{I}$ of $n$ intervals $[s_1, f_1], ldots, [s_n, f_n]$ along a real line, find a minimum number of points $P$ such that each interval contains some point, that is $forall I in mathcal{I}: Read More …
Problem Detail: The Existential Theory of the Reals is in PSPACE, but I don’t know whether it is PSPACE-Complete. If I believe that it is not the case, how could I prove it? More generally, given a problem in some complexity Read More …
Problem Detail: I always thought that TSP currently requires time exponential in the number of cities to solve. How, then, has Concorde optimally solved a TSP instance with 85,900 cities?!? Is this a typo? Is the base of the exponential 1.0000000000000001 Read More …
Problem Detail: I want to prove that grammar $$ begin{cases} S’rightarrow S Srightarrow aSb ~|~ A Arightarrow bA~|~b end{cases} $$ isn’t $LR(1)$. I’ve constructed parser table and got Shift-Reduce conflict. I want to prove that without parser table, using another $LR(1)$ Read More …
Problem Detail: It’s known that the following language, the so-called acceptance problem is undecidable: $A_{TM} = {langle M,wrangle,vert,Mtext{ is a TM which accepts }w}$ The proof is by contradiction: Assume there is a TM $H$ which decides $A_{TM}$. Let $D$ be Read More …
Problem Detail: I’ve googled this problem somewhat pretty extensively, and all the relevant literature understandably deals with 2-d or 3-d cases, rather than the n-d case. EDIT: Yes, ℝn. I’ve done many searches combining terms like union, intersection, volume, convex hulls, Read More …
Problem Detail: I have $ntimes k$ matrix with $k<n$ and I would like to find all its $nchoose k$ submatrices which are $ktimes k$ matrices that are the concatenations of all possible $k$ rows. Actually I tried to do it with Read More …
Problem Detail: In famous Structure and Interretation of Computer Programs, there is an exercise (1.14), that asks for the time complexity of the following algorithm – in Scheme – for counting change (the problem statement suggests drawing the tree for (cc Read More …
Problem Detail: For every computable function $f$ does there exist a problem that can be solved at best in $Theta(f(n))$ time or is there a computable function $f$ such that every problem that can be solved in $O(f(n))$ can also be Read More …
Problem Detail: Consider a four stage pipeline, and each stage has delays D1, D2, D3 and D4, so the total delay because of the various stages should be N * (D1 + D2 + D3 + D4) where N is the Read More …
