Questions tagged [algorithms]
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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What is the most effective algorithm to evenly distribute n points on a 2 dimensional array so they are as separated as possible?
I am trying to code a game which currently uses a matrix ( that I am calling a map). On this map are islands which can be generated n times. The purpose of the algorithm is to distribute the islands ...
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C# How to correctly work with ProgressBar? Architecture look
I am wondering about the correct architecture to work with a progress bar in C#. But maybe it applies not only to C#, because I need an architectural look at this.
I'll explain my question with an ...
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Algorithm for finding optimal appointment times
There are multiple types of appointments, each with their own length. The goal is to find 'optimal' placements for a given appointment type on a given day - optimal meaning leaving as little 'wasted ...
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What do I not understand about Alpha-Beta-Pruning in Chess?
I'm trying to write a chess engine, Min-Maxing works. Now I wanted to implement Alpha-Beta-Pruning, but despite reading about it and watching videos, I must have a severe misunderstanding somewhere.
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Simulate running/resting heart rate BPM
I need to simulate & output the human heartrate BPM with real-world like values. I've been looking at a gaussian random approach but don't believe this fits my use case. I'm not concerned about ...
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Marrying disparate datasets in stream
Caveat: I'm conscious that this question may not be a great fit for stack-exchange platform as maybe 'too broad' but will try & structure it that it helps people in the future
I have 2 event ...
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How large-scale production web crawlers improve performance when it comes to running into already visited links
I have built a very basic webcrawler running off my laptop so it has limited memory and limited hard drive space. The way I have it now is I'm using MongoDB to store the links I find on pages. I make ...
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How to check for ID uniqueness on large dataset that can't fit into memory or on a single disk
Say I have 500MB of memory to work with, but 100 terabytes of IDs I want to generate. I want these IDs (GUIDs) to be randomly selected and applied to records, so they shouldn't appear in order when ...
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What algorithm to count user click/read/turnover for a period of time?
We tried to develop a kinda-real-time statistics module to measure how hot/trend a content is. We know it is hard to achieve high end stuff like youtube/FB/twitter, our goal is simpler :
Count click/...
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Calculation On Large File Data
I have a task where I need to read a big data file and process the data in it. Every row in the file looks like this:
CustomerId ItemId Amount Price
I need to calculate the total cost for the ...
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If the whole point of recursion is to break the problem into multiple smaller problems, what if those problems were solved in parallel?
So I was studying here and I was thinking if the whole point of recursion is to break the problem into multiple smaller problems, what if those problems were solved in parallel? A quick search lead me ...
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Algorithm for permutations of a string of characters, with no duplicate orders
I've seen a lot of good questions about similar problems but not exactly what I'm looking for.
Given: a non-unique set of symbols (or characters)
(1, 1, 2, 3)
Expected: an output similar to this (...
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Bin packing with "flexible" items: Does this algorithmic problem have a name? [closed]
I have stumbled upon the following problem: I have one list of containers with "capacities", and a list of items with quantities. I want to assign those items to the containers. The total capacity of ...
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Arranging blocks of data for efficient memory access
Suppose I have an algorithm that has N blocks of data, and an operation needs to be performed on all blocks such that it requires 2 blocks to be in memory at any given time to be done for all possible ...
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Is algorithm performance dependent on the programming language used? [closed]
I have studied complexity of algorithms that how long an algorithm will take to execute completely, then why it is said that certain programming languages are faster than others such as C++ is faster ...
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How to design a high-scale, reliable, distributed and periodic task (cronjob) execution service?
Assume you are tasked with implementing a "cronjob as a service" where you are supposed to be able to run potentially millions of periodical tasks (to simplify, making HTTP requests to URLs) with ...
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How to implement adaptive routing?
I need to send jobs to worker queues according to resource usage and other metrics like how many jobs have been processed and how successful they were.
There is also the need to “weight” these ...
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How to create a recommendation algorithm ("If you like X and Y, you might like Z")? [closed]
How to create a recommendation algorithm ("If you like X and Y, you might like Z")?
I want to create an algorithm which recommends "You might also like" items from an itemlist, based on user's ...
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When to use Quicksort instead of MergeSort? [closed]
I have the following homework question: You develop a video surveillance software that must run on real-time data. In one of the steps of the algorithm executed with each image captured by the camera, ...
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How to shuffle a large data set without touching every row?
Let’s say I have two larges arrays of users with equals number of rows and I want to match them randomly and one to one(one from the first array,one from the second), I will first need to shuffle one ...
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Transforming a long-running operation into a step by step operation?
I am working on a video game in Unity and at some point I'm facing a tough problem to solve:
The game freezes while loading level data.
Let me lay down what's happening in that process that takes a ...
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Algorithm for Parking Space Allocator System
In my office, there are 200 employees who come to the office in their car. But my parking space has slots for parking 160 cars only. Now I want to design and develop an application that issues parking ...
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What is the right algorithm to solve this problem?
The problem is -
We have a series of boxes (A, B, C, D, ...).
Each box contains bricks of different colours. For eg.
Box A - red, blue
Box B - blue, red, green
... and so on...
and there are ...
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Distribute jobs evenly among a set of servers
I have the need to distribute a set of long running jobs across a cluster of containers in ECS. These jobs essentially would need to open a socket connection with a remote server and begin streaming ...
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How to Define the Bandwidth in Mean Shift Clustering?
I am making a program using Java todo colo quantization using mean shift clustering algorithm and the image is RGB with resolution of 512x512. I want to reduce the image file size by reducing the ...
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How to join two sets of 6 tables and select the list into another set of 6 tables
A1
|__A2
|__A3
|__A4
|__A5
B1
|__B2
|__B3
|__B4
|__B5
C1
|__C2
|__C3
|__C4
|__C5
Given a list of A and a list of B, we want to "join" ...
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How can my distributed web service rate-limit calls to a downstream component?
Context: I own a service that's distributed across VMs, that themselves are distributed across multiple data centers.
Scenario: I'm adding an API that calls a single downstream dependency. This ...
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Provide iterator while generating power set [closed]
I have written a code in C# to generate the power set of a given input list of integers.
public List<List<int>> GeneratePowerSet(List<int> Set)
{
int setCount = Set.Count;
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Gerstner Wave equation from tessendorf paper, mesh penetrates itself
I have been learning to create water waves in a mesh from a paper commonly known as the Tessendorf paper. Which is quite well known.
But those who don't know this is the equations it mentions in the ...
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Do we include output space in space complexity?
For example. I have a function which generates an array with random numbers.
int[] generateNum(int n) {
int[] result = new int[n];
/* Logic to generate random number */
...............
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How a Merkle tree can work with Graph data, or a better data structure
I am looking at blockchain and trying to see how Merkle trees (or perhaps Merkle DAGs) can fit to a graph data structure with circular references.
For example, say I have this data model:
var ...
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Algorithm - Simulation of a soccer match
I'm implementing an App for fun. It consists of a soccer round-robin tournament simulator in which all teams play each other. A Team consists in a simple object:
class Team{
String _teamName;
...
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Algorithm. Find the group of documents with the least amount of words
I need help with a problem which I have been working for the last month.
I have a group of documents, each document has a set of unique words (if the word appears more than once in the document, I ...
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Calculating activity score based on log in activity?
I have a site where user logs in. I need to calculate the log-in activity score based on the age when he logged in. For example :-
If user logins today he will have high score than the user who ...
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Sorting an array of ranges for display
I have an array of ranges with start and end timestamps. I want to display those ranges on a graph.
Right now, my naive algorithm gets an array of ranges sorted by their start timestamp and
iterate ...
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Can the Mean Shift Algorithm be used in color quantization?
I have a problem with deciding algorithm for color quantization. The image that I want to do color quantization is an RGB image with resolution 512 x 512. I want to reduce the color value in the pixel ...
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storage of text history and algorithm to return text at particular time
An application I'm considering writing needs to show a text that a user has edited at a particular time.
So consider if we have a text the user is editing from Time A to Time X, and I want to show ...
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Performing complex searchs using C# collections
I have a collection with millions of items of Generic type T. Assume this list never changes.
I want to perform many types of searches with subsets of fields of type T. Some with only 1 field and ...
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Algorithm to simplify 2D convex hull at the cost of extra area
Are there any algorithms related to the following problem that could be usefull for solving it?
I have a convex hull built on some point set.
I would like to simplify it (reduce number of points) by ...
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Low resolution Image to High resolution
Is it possible to scale a low resolution image to a highier resolution upto the point with minimum effect on quality, sharpness and other notable attributes of an image.
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Is my algorithm for determining whether a ipv4 is public or private correct? [closed]
I have just created a function which checks whether a ipv4 is public or not. I have not heavily tested it yet since it is kind of practically impossible to do so (because I do not know where to start)....
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How can compare two integer with only using ==, + and recursion?
Here is the original question from MIT lecture notes :
Write a Spy procedure that takes two positive integers as input and returns True if the first is greater than the second. Use only the ...
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How to optimize a mixed stack/register bytecode with control flow and side effects?
I'm trying to figure out a technique to optimize bytecode for the following virtual machine:
Bytecode is a flat list of instructions, with execution starting from the first instruction.
Stack ...
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Is this a sorting algorithm faster than O(n*log(n))
If there are n variables each with m possible values. (For integer, m is 2 billion something.)
First, map every possible value to an integer from 0 to m-1 in order.
And define the mapping functions.
...
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How to determine the collection type without access to the source code [closed]
How could you determine if a collection is implemented as an array or as a linked structure without access to the source code (assuming you can run the code)?
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Difference array to range array updates
I found information that the best way to update ranges of array values is using difference array. It works but I can't figure out why it works.
Can anyone could explain it for me?
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Finding an efficient data structure and/or algorithm
I am tasked with an animated graph based on a timeline, and I am having trouble finding a suitable data structure and/or algorithm that's reasonably efficient. I have a working system suffering from ...
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Aggregation of data from two Microservices
I have two Microservices A and B.
B Microservice has a large set of an entity called User.
A Microservice stores the User entity in its own DB if User is configured by an agent. There is no flag ...
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Why is stability considered a desirable trait of a sorting algorithm?
The common argument for stability in a sorting algorithm typically involves an example where a list is sorted by two criteria. For example:
1,4,5,7,2,6,8,9,15,65,24,27
sort by evenness/oddness and ...
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What is recommended way to create test data for unit test cases?
I am new to TDD/unit testing.
I am going to write a complex scheduling algorithm in Java. As this module is a core part of our application and there are number of scenarios in it, I want to write ...
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