How to generate a subdivided icosahedron?
I've asked some questions here and seen this geometric shape mentioned a few times among other geodesic shapes, but I'm curious how exactly would I generate one about a point xyz? ...
algorithm
Identifying Algorithms in Binaries
Does anyone of you know a technique to identify algorithms in already compiled files, e.g. by testing the disassembly for some patterns? The rare information I have are that there is some (not exported) code in a library that decompresses the content of a Byte[], but I have no clue how that works. I have some files which I believe to be...
Where can I find a lossless compression algorithm, which produces headerless outputs?
Does anyone of you know a lossless compression algorithm, which produces headerless outputs? For example do not store the huffman tree used to compress it? I do not speak about hard coded huffman trees, but I like to know if there is any algorithm that can compress and decompress input without storing some metadata in its output. Or is t...
Clustering Algorithm for Paper Boys
I need help selecting or creating a clustering algorithm according to certain criteria. Imagine you are managing newspaper delivery persons. You have a set of street addresses, each of which is geocoded. You want to cluster the addresses so that each cluster is assigned to a delivery person. The number of delivery persons, or clusters...
What's a good way to study algorithms?
Duplicate of: How to get started on algorithms After overloading my classes one fateful semester in my college days, I ended up dropping my algorithms course and never taking it again. I'd like to finally fix this by doing some self study, but I'm wondering how best to approach it. I've got a few algorithm texts, notably the CLR...
Recommend some Bresenham's-like algorithm of sphere mapping in 2D?
I need the fastest sphere mapping algorithm. Something like Bresenham's line drawing one. Something like the implementation that I saw in Star Control 2 (rotating planets). Are there any already invented and/or implemented techniques for this? I really don't want to reinvent the bicycle. Please, help... Description of the problem. ...
Formula to determine whether a line form by 2 geo points (lat, lon) intersects geo region (circle)?
It does not need to be very accurate. Does anyone know a good way to do this? any help is much appreciated. ...
Nav menu - Rendering dividing pipe characters
Hello. I have a webcontrol with a handful of links displayed at the top, eg: Link 1 | Link 2 | Link 3 Currently they're each an asp:Hyperlink. Is there a clever solution for rendering out the dividing pipe characters? Currently they're within the containing placeholder. We can't make any guarantees about a given link always appearing...
2/3D Geometry: How to optimally align two lists of points
The problem I am trying to solve is as follows: Given two lists of equal length containing points, find a mapping that minimizes the sum of distances between pairs. The reason I'm trying to do this is to find the closest points in two polygons for a genetic algorithm I'm building, that would ideally line up two genes based on the output ...
Poor man's authentication algorithm?
Brainstorming request I need an idea for an authentication algorithm with some unusual requirements. The algorithm would be used to verify that the sender of a message is legitimate. Restrictions: The "transport layer" is e-mail the sender ('Alice') is a human being Alice only has access to a web browser and internet access (includi...
How to calculate distance from a GPX file?
I have a GPX file with a GPS track. Now I want to calculate the distance I covered with this track. What's the best way to calculate this? ...
Algorithms for helping humans choose (kitten war, for instance)
Ok, I'm facing an imminent addition to my family, and working through choice of names. I've considered writing software to display names and force me to choose which I like better, similar to kitten war. Once I've got a huge graph, though, I don't know how to process it, especially if there are cycles. for instance, I like mike better...
Building or Finding a "relevant terms" suggestion feature.
Given a few words of input, I want to have a utility that will return a diverse set of relevant terms, phrases, or concepts. A caveat is that it would need to have a large graph of terms to begin with, or else the feature would not be very useful. For example, submitting "baseball" would return ["shortstop", "Babe Ruth", "foul ball",...
Best algorithm for evaluating a mathematical expression?
What's the best algorithm for evaluating a mathematical expression? I'd like to be able to optimize this a little in the sense that I may have one formula with various variables, which I may need to evaluate hundreds of times using different variables. So basically if I can initially parse the formula so that it is optimized in some way,...
Algorithm for syncing the order of entries
This is client/server application system. Client-part application can go off-line mode and sometimes syncs with server. (like GMail offline) More than one client can connect to server, so each client can add, edit and remove its entries and synchronize these changes like SVN (the collision can be happend, but it's not a problem.) The ...
Which algorithm for assigning shifts (discrete optimization problem)
I'm developing an application that optimally assigns shifts to nurses in a hospital. I believe this is a linear programming problem with discrete variables, and therefore probably NP-hard: For each day, each nurse (ca. 15-20) is assigned a shift There is a small number (ca. 6) of different shifts There is a considerable number of const...
How to cultivate algorithm intuition?
Hi, When faced with a problem in software I usually see a solution right away. Of course, what I see is usually somewhat off, and I always need to sit down and design (admittedly, I usually don't design enough), but I get a certain intuition right away. My problem is I don't get that same intuition when it comes to advanced algorithms....
Quicksort terminology? (like fat pivot)
Does anyone know the full technical vocabulary to describe all the various versions of quicksort? The one I know is "fat pivot"[A] (where all items matching the pivot placed in the middle of the subarray and excluded from further sorting). The ones I'd like to know are when one element (the pivot) is placed in the middle and excluded fr...
Handling selection of shapes on a board (algo)
I have a board as a canvas with several shapes drawn on it, some of them are triangles, circles, rectangles but all are contained inside their own bound delimited rectangle. "The circle will be inside a rectangle" I put two circles A, B on the board where A is over B and has some area colliding. If I click on A area corresponding to th...
Guaranteeing Unique Surrogate Key Assignment - Maximum Matching for Non-Bipartite Graph
I am maintaining a data warehouse with multiple sources of data about a class of entities that have to be merged. Each source has a natural key, and what is supposed to happen is that one and only one surrogate key is created for each natural key for all time. If one record from one source system with a particular natural key represent...