Author: ignougroup

Problem Detail: Given a set $S$ of $N$ points on a sphere, and another point $P$ on the sphere, I want to find the $k$ points in $S$ that are the closest (Euclidean or great circle distance). I’m willing to do Read More …

Problem Detail: There are $n$ pairs of socks, all different. They all went out of the dryer, so there are now $2n$ socks scattered around. Given two socks, the only operation I can do is to decide whether they are identical Read More …

Problem Detail: I’m being asked this question for my computer conceptes class, can’t find anything about this in my text book, and have only been able to find half-baked answers googling it. Why is binary subtraction referred to as the invert-add-shift-add Read More …

Problem Detail: Suppose that I have a turing machine that receives as input the string $1^{ntimes n}$ (unary input), what is the time complexity of writing $p_1,…,p_n$ on the output tape, where $p_i$ is the i-th prime number (written in binary)? Read More …

Problem Detail: This is part of a larger problem, which I believe I have reduced to this. Given a tree $T$ having positive edge weights, and $k$ leaves (nodes which have exactly one connected node), I need to delete some edges Read More …

Problem Detail: I am working on a problem where I am supposed to count the number of arrays of size $Ntimes M$ where the sum of elements in the $i$-th row is greater than or equal to the the sum of Read More …

Problem Detail: I have to explain how a 2-PDA works and then write a program (in Delphi) which simulates a 2-PDA step by step for the language $L = {w$w | w ∈ {0,1}^n with n>0}$. So far, so good. Now Read More …

Problem Detail: You have $n$ sticks of arbitrary lengths, not necessarily integral. By cutting some sticks (one cut cuts one stick, but we can cut as often as we want), you want to get $k<n$ sticks such that: All these $k$ Read More …