In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning.

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Algorithm to generate Edges and Vertexes outwards from origin with max multiplicity of 3

I am creating a 2d game for a website where the universe can grow extremely large (basically infinitely large). Initially, the universe is composed of 6 stars that are an equal distance from the ...
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148 views

Combinatorial Optimization: Filling a Bag with Sand

I have an interesting "real-world" combinatorial optimization problem that I need to solve programmatically, however I have yet been able to whiteboard a good strategy. The task is similar to the ...
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398 views

Dynamic programming in Bin packing

Problem: Given a list L of objects of possible sizes from set S={1,2,4,8} and unlimited supply of bins of sizes 16 each and we have to use minimum possible numbers of bins to pack all objects of L. I ...
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262 views

Help/suggestions for Parallel assembly line scheduling (Dynamic programming)

I am working on a problem similar to the assembly line scheduling by dynamic programming.The issue is that unlike the classic problem where we have predefined stations now I only have information ...
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212 views

Automatic Appointment Conflict Resolution

I'm trying to figure out an algorithm for resolving appointment times. I currently have a naive algorithm that pushes down conflicting appointments repeatedly, until there are no more appointments. ...
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55 views

Generate quantity distribution of objects to reach goal for each attribute

The Problem Suppose we are given a variable-length list of objects containing a fixed-length list of positive decimal numbers as attributes. JSON Example [ {a: 0.1, b: 0.6, c: 0.0}, {a: ...
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322 views

Fast fixed-size (256 bit) integer modulo/division

What is the fastest way to divide two 256-bit integers? They are represented as an array of 26-bit words, each stored in 32-bit integers. I have access to a 64-bit type if that's useful. It seems ...
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274 views

What algorithm is this?

I have some vague recollections from my algorithms courses, but nothing specific comes to mind. let S be a multiset of things we are interested in. As input, we get T, s1, s2, ... sn, all of which ...
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34 views

Polygon simplification that encloses original set of points

I have been trying to implement an optimization for 2D sprite rendering to fight the problem of limited fillrate on mobile devices. The idea is to render textured polygons instead of quads that will ...
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94 views

Predicting package delivery schedules

I'm trying to solve the following problem: A delivery man has N packages to deliver, already sorted. He starts the route at start_time, he works until end_time. I have historical data of his ...
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100 views

How to distribute the number of elements in a bucket so that it is Within a Range - Algorithm

I have been solving a problem where in say I have 50 elements n1, n2, n3, ... , n50 Now I have a limited number of buckets, say 5 buckets and the bucket can hold a range from , say 100 to 150 only ...
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91 views

Creating a better mouse dragger function

I originally posted this to code review, not knowing incomplete code was off-topic and was pointed to post here. I don't believe this question is a good fit for stack overflow because the code I ...
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47 views

Project a piece of image cut by N-vertex shape to a different N-vertex shape

I have an N-vertex shape that I cut out from an image, and I want to project it onto another shape with the same amount of vertices, but different. So, the image will get changed inside the ...
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45 views

Optimizing trigram look ups with wildcards

I am working on creating a spell-checking service for Android (note: this is a platform- and language-neutral question) for Asturian, a minority Romance language. We're using hunspell as the base but ...
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117 views

Smallest number of rectangles covering marked parts of grid

I have an N by N grid of cells, and certain blocks are marked: +--+---+---+---+ | | | | | | | x | x | | | | x | x | | | | | | | | | | | x | +--+---+---+---+ I would like to ...
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106 views

Asking questions to the user based on results of previous questions

I have to select a question that would help me make me sure the user knows about a given subject. As an example, let's assume the user hasn't answered any question yet. Every question has a scope ...
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157 views

Design an algorithm with network flow

Given a matrix A with 0 and 1 entries. Neighbours of a[i,j] are a[i-1,j], a[i+1,j], a[i,j-1] and a[i,j+1] (if exists any). Tow neigbour entries are an Improper pair if they have not equal values. if ...
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165 views

Walk Tree vs Zhang and Sasha Algorithms

I need some help understanding how two tree comparing algorithms differ. I am working with Microsoft's XmlDiffPatch (http://msdn.microsoft.com/en-us/library/aa302294.aspx) which compares two xmls. The ...
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143 views

Incorporating custom Algorithm in SOLR-LUCENE , before Indexing?

CURRENT FLOW: I am using a custom algorithm(presently in php) to rank the MYSQL records before INDEXING it to SOLR . WHAT I WANT : Is it possible implementing this ALGORITHM(may be in JAVA) inside ...
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587 views

How to find minimum weighted vertex cover of a tree, and confused about a solution

Studying for my algorithms test by spamming Algorithm Design Manual exercises, but I'm stuck on this one. I know I have to keep score somehow. Let G = (V,E) be a tree with arbitrary weights ...
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69 views

Calculating “instability score” for connection quality, programmatically

First of all, apologies if this is posted in the wrong site. I thought it is more suitable here than SO because the question is quite generic, more an algorithm question than a specific programming ...
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144 views

Colour curves tool for “value” channel

I'm trying to write a program to read GIMP curves files and apply them to an image. I have successfully implemented the curves for the red, green and blue channels, but I can't get it working for the ...
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255 views

Match buyers and sellers based on date ranges and quantity of shares

NOTE: This is in reference to the question I asked on Stack Overflow but was told to post this here I'm building a trading application that matches buyers/sellers that own subscription. Subscriptions ...
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178 views

Solving geometric constraints with Minion

I am doing research on squares, and I thought of using constraint-satisfaction-problems solvers for proving or disproving some conjectures. As a simple example problem, consider the following task: ...
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243 views

Generate complex (non-convex) polyhedron UV mapping

I need to find an approach to the problem of generating texture maps for non-convex polyhedrons without using a design tool like Maya. Specifically, I am mapping simulation results data onto a 3D ...
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43 views

Find minimum number of steps to a goal without estimator for how close intermediate steps are to the goal

I've been trying to find a good way of solving the following problem, but I'm not sure how to even frame it. I think there might be relatively well-known solutions I'm not familiar with, since I don't ...
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39 views

Graph grouping with criteria

I start with a list of adjacent tetrahedra, where there are tight seals to one another along faces for two tetrahedra that are adjacent. The vertices belonging to these faces for both tetrahedra are ...
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66 views

Belman-Ford 2d array variation problem

I've got a problem with applying a Bellman-Ford algorithm to 2D Array (not to graph) Input array has m x n dimensions: s[1,1] s[1,2] ... s[1,n] -> Exit s[2,1] s[2,2] ... ...
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89 views

Finding the longest acyclical path in a 2D maze

I have a n by n maze, like this: [0, 1, 0, 0, 0, 1] [1, 1, 0, 1, 1, 0] [1, 0, 0, 1, 0, 1] [0, 1, 1, 0, 0, 1] [0, 0, 0, 1, 0, 1] [1, 0, 1, 0, 1, 1] Only 0-fields are passable, and one can only move ...
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63 views

Generate a fixed length number hash from a number

Let say I've a fixed length number, e.g. 6 digit: 837493, I want to apply some process (with a salt), and generate a new number of another 6 digits, e.g. number = 837493 another = hash(number + ...
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68 views

distribute rectangles in order to do not overlap

I've a series of labels and icons inside the screen. A label is on the right of corresponding icon. I must perform a sort of declutter: when two or more labels overlap each other (or a label with an ...
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32 views

Matching data based on multiple parameters and certain limits

I've been looking into the k-nearest neighbors algorithm as I might be developing an application that matches boxers in the near future. The reason my for question, is to figure out which would be ...
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45 views

Recursive(?) algorithm design help

I have a requirement to allow my end users to input formula much like a spreadsheet. I have an array like this: $table = array( 1=>array( "id"=>1, ...
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89 views

Search algorithm on sequential data model

For sequential data models like LinkedList, search algorithms like linear-search and binary-search are well known. Are their any other search algorithms apart from these two, that work on sequential ...
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61 views

clustering of strings with variable-length prefixes

I've got bunch of strings with variable-length prefixes (or postfixes - I can always revert them) as follows: 0155555555 523455555555 755555555 ... 87129999999999999 119999999999999 09119999999999999 ...
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84 views

Efficient extensions of degree of separation

I'm trying to play around with the 6 degrees of separation problem, specifically the Kevin Bacon game to find alternative ways of playing the game. I want to eventually port it over to MapReduce, but ...
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82 views

Choose a number of arrays which have the smallest cardinal number when unified

Say we have multiple arrays: var a := [1, 2, 3] var b := [2, 3, 4, 5] var c := [1, 3, 4, 6] var d := [1, 2, 5] We want to find the three arrays with the smallest cardinal number when the three ...
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115 views

Reversing dithering algorithms?

I was trying to make an implementation of the Floyd-Steinberg dithering algorithm in Python, and I was wondering, since Bitmaps files store their data starting from the bottom-left corner, would it be ...
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76 views

Combining items from several lists with pagination

I am trying to come up with an algorithm for getting items for a news feed from several sources. There are multiple lists of data: S1, S2, ... Sn. Each of these lists has a certain known amount of ...
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51 views

Can't figure out how to parallelize the calculation of the amount of offspring expected for species in genetic algorithm

I developed a genetic algorithm in java 8 taking advantage of its reasonably free parallelism opportunities with Streams. As you are likely aware, running the epochs takes its time for even a test ...
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51 views

PSO – how Dimensions are set up?

I am coding a Particle Swarm Optimization in C++. I have been for days trying to understand the theory of how dimensions work in each different problem. In the many examples I have seen, all of them ...
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73 views

A fast algorithm for a simple multi-objective minimization?

I have a set of n (arbitrary) integer numbers S which I want to partition into k subsets S_i each of size n/k (you can assume that k divides n). Let A be the arithmetic mean of elements of the set S. ...
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36 views

Finding the largest bundle of flagged points

I am currently working to develop a program that takes in an array of 4 columns and around 200,000 rows. Each column represents x, y, z (coordinates), and a flag denoting whether or not this point is ...
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109 views

Dispatch Algorithm for logistics - Batch assignments

basically, I'm trying to implement an algorithm that dispatches drivers to deliver batches (a batch is a collection of orders). The algorithm takes all the batches and all the drivers available, then ...
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214 views

Algorithm for sweeping a 2d shape along a curve?

I am trying to create a graphics application where the user can use an arbitrary shape as a "brush", which will be swept along the drawing path. The shape may be transformed along the path (rotated, ...
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201 views

Algorithm for sport tournament bracket tree

I would like to develop a library that: receive n players in input response with the tournaments brackets in output. I would ask you what kind of algorithm I have to use to choose the correct tree ...
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118 views

An algorithm to implement SQL's ORDER BY with TOP/LIMIT or OFFSET/FETCH

Is there a general algorithm to implement SQL's ORDER BY with OFFSET/LIMIT more efficiently than sorting all the records? The algorithm for a simple TOP x is easy enough. It takes one full pass ...
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324 views

Tournament bracket customized algorithm

I'm in the making of a tournament for archery but i'm stuck because they want a specific match-matching for players. There is the usual 1-32,2-31,3-30 etc but the way they want the tree is a specific ...
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163 views

Is this synchronization required in service onCreate method?

Below is a sample code i captured from android doc Per service instance onCreate will be called only once. Ref: here and here The synchronization and singleton doesn't make any sense to me in this ...
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551 views

how to use Sql query to search text in CSV file and avoid iteration

I have one A File and many input files ,All files have CSV format . I want to match text of one column of all input files with one of the column of A file . I have stored all column value of File A in ...