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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3
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1answer
155 views

Neighbourhood points (2d)

I have a 2d coordinates system with some points on it, like this one: Now I am looking for an algorithm (or just some approach) to find neighboured points. So, if you have the coordinates of one ...
1
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1answer
75 views

Determine what to draw based on neighbour tiles?

I have a tilemap and I want to add walls to it. I painted 16 images, one for each possible combination. For example: A lone wall tile would get a image that has walls around. A corner would get ...
0
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2answers
107 views

Extract significant locations from GPS readings

I'm writing an app that continuously monitors user location 24 hours a day using a mobile phone with readings every 5-30 mins (about 50-300 readings a day). How do I cluster readings and extract user ...
3
votes
1answer
132 views

How to find the closest vector to a given vector?

Let's say I have several points / vectors (in 2D to keep it simple, but could be of any dimension) [x1, y1] [x2, y2] [x3, y3] .... [xn, yn] If I pick some point [x', y'], how do I ...
2
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2answers
104 views

Generate pips on a die based on value

Is there an algorithm to generate the pips on a die or domino? I know that there is usually an odd number of columns and even number of rows (unless the max number of pips is not a perfect root). ...
4
votes
2answers
503 views

Why do textbooks use pseudocode rather than real languages?

In colleges and in algorithm textbooks, it is quite common for the teacher and author to explain control flow in pseudo-code. With the advent of more expressive languages like Python and Haskell among ...
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2answers
121 views

Algorithm to detect if a list of strings need delimiters

I need to write a function to detect if a set of strings needs delimiters when concatenated in any order. For example, the strings ("A","B","C") do not need a delimiter: "ABCBB" -> ...
1
vote
1answer
45 views

Patching data by identifying and copying repeating pattern

I have a dataset sampled with a specific pattern (timestamps). The very first repetition of the pattern is damaged, meaning that the values are nonsense. To exemplify, my data looks like this: data = ...
1
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1answer
31 views

Sorting algorithm for Provides/DependsOn objects

I have a set of type rewriters, each modifies a given C# type in a different way. Examples are: Add the XYZ attribute to each property of the class Add an ID property Add two properties and some ...
2
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2answers
194 views

Merge sort and O(n log n) mystery

I read every explanation here but still not convinced. I think mergesort is n * n and I know I am wrong but not sure where. Here is what I think: Suppose we are sorting 8 elements and this is the ...
3
votes
5answers
248 views

How to calculate winning chances of one poker hand against another? [closed]

My question relates to Texas Hold'em Poker. But I believe it will be the same algorithm for any kind of poker game. So let's consider two hands: AJo and KQo. I can use online calculator and find out ...
1
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1answer
202 views

What is the meaning of “static” in pseudo-code

This is a pseudo-code from "Artificial Intelligence: A modern approach" function Table-Driven-Agent(percept) returns action static: percepts, a sequence, initially empty table, a table, ...
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votes
1answer
98 views

Find missing number in sequence in string [closed]

I have a string that contains numbers in sequence. There are no delimiters between numbers. I have to find missing number in that sequence. For example: 176517661768 is missing the number: 1767 ...
1
vote
1answer
85 views

How to “de-dupe” similar lines (detected using the Hough Transform as rho/theta pairs)

I'm trying to identify an object (a cube) in a set of photos. Using Canny/Sobel/Hough I've managed to get the photo down to a set of lines that are pretty accurate; however if I plot these lines on my ...
0
votes
1answer
26 views

Extract the main entity from a body of text for text categorisation?

I'm trying to categorise products based on various fields of data. I've had some success just matching search terms in the product names, but this naive approach doesn't work when it comes to larger ...
0
votes
1answer
124 views

Algorithm to get all possible forms of a word with varying suffixes [closed]

I'm writing an application in javascript where given a word, I need to get all the possible versions of the word with the suffix being the difference between each form. For example: "sponsor" should ...
4
votes
4answers
210 views

Selecting a CPU or microcontroller needed for a given software application?

Say I had a software algorithm (for example, an FFT), and I need it to process (n) amounts of data in (t) milliseconds. This is a real-time task written in C. There are a lot of CPUs out there, and ...
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votes
1answer
50 views

Considerations when making data structure and algorithm choices [closed]

What are some reasons you may choose a worse runtime algorithm? And what are some advantages of a linked list vs a hash table/array where access is constant time.
1
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1answer
47 views

Implementing CMA-ES

I am attempting to implement the CMA-ES optimization algorithm in my favorite language (using the example code here as a guideline), but I need help solving a problem I am having. To test the ...
2
votes
1answer
241 views

Word game algorithm

Back in the days of 8-bit machines there existed an educational word game. I have no idea what it was actually called but for the sake of this question (since it involves pyramids) let's call it ...
3
votes
1answer
87 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 ...
8
votes
3answers
279 views

Generate equally sized areas in polygon

I am looking for a pseudo code logic that would find n equally sized areas in a given polygon. No space should be between or outside the matched areas. First valid match of areas should be returned. ...
2
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0answers
40 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 ...
2
votes
0answers
181 views

Find all paths in a tree type of structure

The language I am using is C#, but I am looking more for help with the algorithm more than I am concerned with which language. I have been trying to develop this algorithm for a while now and I can't ...
0
votes
2answers
267 views

How to approach hours forecasting

I need to forecast budgeted hours for 2 departments to help them schedule staff as currently the best they can do is just wing it. When we receive a job proposal I'll have the person submitting the ...
3
votes
1answer
170 views

Divide the world map into fixed sized blocks

I am developing an app where I need to divide the entire world map into fixed sized square blocks. For simplicity, think of it as a problem of dividing the google maps into a fixed sized block. I can ...
3
votes
1answer
91 views

Prorating a license (its expiry) dependent on feature add-ons

I've ran into a problem trying to calculate prorating of a service. Hoping to get some help/hint from the community. I apologize if this isn't the right place to ask this question - will appreciate ...
6
votes
1answer
142 views

Finding similar high dimensional vectors

I have two lists (sizes m and n) containing high dimensional bit-vectors. All vectors have the same number of dimensions and use Hamming distance as measure if distance. For each element in the first ...
0
votes
2answers
157 views

Optimization problem where to start, what algorithms to use? [closed]

I have an optimization problem and I was wondering where to start from to be able resolve it. I think it can be solved with an NP-complete algorithm but I am not sure where to start from. The problem ...
2
votes
2answers
77 views

Retrieving an incorrectly stored tree data structure

Way back in the hazy origins of our platform it was decided that we were going to need some hierarchical data structures stored in the RDBMS. The relationships between nodes were stored via a ...
2
votes
1answer
111 views

Improving sampling algorithm

I am having a bit of trouble designing a new feature at the moment. It is part of a resource management system. I was wondering if anyone has experience doing anything similar. I'll try to explain: ...
4
votes
1answer
171 views

JavaScript functional conversion from flat list to tree

I've been going through the RxJS tutorials http://reactivex.io/learnrx/. Almost all of the exercises involve moving from a hierarchical structure to a flat structure so I thought I'd try to do the ...
3
votes
0answers
62 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: ...
4
votes
1answer
136 views

Name-Based Sorting Algorithms For Maximized Common Letters

I am attempting to write a program for a competition (we're allowed to consult Stack Exchange, as long as I'm not given physical code) that takes in a list of 5000 people's names (distributed fairly ...
1
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1answer
191 views

Algorithm to get all paths in a tree

I have a tree that has n-levels. For example here I have four levels: Each node has two children (except for the last one), however everyone except for the first and last node of each row has two ...
2
votes
1answer
124 views

Is this Red-Black tree insertion pseudocode from Introduction to Algorithms (CLRS) correct?

For the Red-black tree insertion fixup the book distinguishes between 6 cases, 3 of which are symmetric. The cases are (z is the node being inserted): Case 1: z's uncle is red Case 2: z's uncle is ...
8
votes
0answers
132 views

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 ...
1
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3answers
158 views

Should I be using any algorithm to sort/find items, or use a language's built-in ways?

I'm currently a first semester IT student, and I'm wondering if it's better to write my method to find something e.g. in a C# List, or to use any built in method to do these, such as LINQ or .Find or ...
4
votes
4answers
323 views

How to design a function that takes a date and gives out a number between 1-6, always the same for all dates

As a part of an algorithm I'm making I need to make a function that takes the current date to a function and gives out a number between 1-6, and not the same number for two consecutive dates. And it ...
-2
votes
1answer
194 views

Create arithmetic expression from number using +-/* that equals target [duplicate]

For example, you are given the source 1234 and the target 24. The task is to use the standard arithmetic operators +-/* placed within source, without changing the order of the digits of source to ...
5
votes
2answers
138 views

Find path of steepest descent along with path length in a matrix

Came across this problem -- You are given a grid with numbers that represent the elevation at a particular point. From each box in the grid you can go north, south, east, west - but only if the ...
0
votes
1answer
235 views

What is a lattice parser?

My friend asked me for help with his task: "Redeem a lattice parser with any programming language" - the problem is that he can't clearly explain me how the lattice parser should work. I've tried to ...
7
votes
2answers
317 views

Efficient algorithm to merge n successive sorted arrays in place

I am developing an in-place sorting algorithm that leaves the array into a state where it is basically a succession of sorted subsequences of any size (most are bigger than log2(size(array))); then it ...
0
votes
1answer
142 views

Do you know the name of this algorithm? (cycle with history?)

Context : I'm a IT student who is trying to implement a small application for my family. Every year, we offer each other gifts. Each one of us pick a name of a family member in a hat, and have to ...
1
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0answers
43 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 ...
4
votes
1answer
73 views

How to generalize the planar case of the closest pair problem to d dimensions?

I'm trying to create a solution for the Closest pair problem using d-dimensional points. I've done a thorough search on google but it seems that there is no explanation for the d-dimensional case ...
3
votes
4answers
585 views

Which algorithm is performant for matrix multiplication of 4x4 matrices of affine transformations

I am wondering what is a good, performant algorithm for matrix multiplication of 4x4 matrices. I am implementing some affine transformations and I am aware that there are several algorithms for ...
4
votes
1answer
130 views

Single Source Shortest Path

In the lecture we are taught that we can solve All Pairs Shortest Path(APSP) with matrix multiplication. In APSP we are creating a distance table for all the distances between each nodes in the ...
0
votes
0answers
70 views

Compute the permutations for a set of numbers and then run each to find every possible schedule that fits a client constraints

I am building a Java program that computes the permutations for a set of numbers and then runs each of those permutations to find every single possible schedule that fits a client constraints. The ...
2
votes
1answer
86 views

Algorithm for best subset of items

I have a matrix M with size NxN where each position M(i,j) is an integer representing the relationship between item i and j. If i and j are the same item then the positions M(i,j) and M(j,i) are 0. ...