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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How can a route finding program avoid obstacles/locations when calculating routes? [closed]

Do you delete nodes from the underlying graph representation? Or is there a more elegant way to do it?
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29 views

Calculating combinations from categories

I'm trying to calculate every possible selection from different categories. 1 choice must be made from every category and the categories are always in the same order. I save a string where each ...
-1
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1answer
226 views

How to create a some kind of value for sentences? [closed]

I want to identify most matching sentence using some pattern. That means by using java algorithm I want to create identical value for each sentences.Each sentence when entering to that algorithm can ...
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37 views

Readers Writers algorithm help - starvation and no starvation

I found this link, as an explanation of r/w problem - http://pages.cs.wisc.edu/~bart/537/lecturenotes/s7.html But, I'm having problems realizing is there any starvation present here and why? Also, if ...
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1answer
109 views

Difficulty implementing algorithms from abstract understanding [closed]

I've got decent programming experience for an undergraduate. I just started the study of algorithms. I read the description and saw visual examples that make perfect sense in my head. But when it ...
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200 views

How to extract the active code path from a complex algorithm

I have been puzzled lately by an intruiging idea. I wonder if there is a (known) method to extract the executed source code from a large complex algorithm. I will try to elaborate this question: ...
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2answers
98 views

Set distances algorithm question

I have multiple sets containing integers. An integer maybe present in one set or multiple sets. I would like to find/match the sets with the most common integers. Example s1 {1, 2, 3, 4} s2 {1, 3, 4, ...
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2answers
239 views

What is a O(n) algorithm to solve this puzzle?

We are going to hold a meeting where everybody will speak in clockwise direction around a table. There are n people with n spots. Each person has a position preference (e.g. some want to go first, ...
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60 views

How do I mutate a value in a genetic algorithm using Gaussian distribution?

I've been reading 'Introduction to Evolutionary Algorithms'. This method is stated, but not described, and I can't find anything more specific online. p44/45 of 2nd Ed for reference. "adding to the ...
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187 views

Heuristic Approach for Flexible DIFF Implementation

I have created a DIFF implementation to compare document revisions at work. It is based on An O(ND) Difference Algorithm and Its Variations. One thing that has become important is to take the list ...
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1answer
531 views

How to develop an algorithm for brute-forcing / backtracking?

As a beginner programmer, I don't know how to conceptually think about brute-forcing. My mind can't really fathom how to write code that will try every possibility. I have a problem that I want to ...
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1answer
193 views

LLVM case: is the success due to the algorithms? [closed]

I'm not sure if this is a subjective question, I hope not but I'm not proficient with LLVM so I'm just wondering: how come it's become so popular and so widespread used in the industry? Were the ...
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1answer
73 views

Efficient algorithm for joining sieves

I'm trying to find an efficient algorithm for the following algorithm. I have a sequence consisting of lists of indices denoting indices to be removed. The semantics are such that each sequence must ...
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4answers
348 views

Building complex algorithms with TDD

I'm trying to adopt TDD in my daily programming practice. I use it at work very effectively, but I'm having trouble with my personal projects where I'm using some complex algorithms. The particular ...
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2answers
239 views

Algorithm to order array

Take for example this input array: [2,7,1,4,9] For this input, I need to produce an array of total 23 elements which contains two elements of 2, seven elements of 7, one element of 1, four elements ...
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3answers
455 views

Least Change Problem with Thousands of Denominations

In a hypothetical economy there are currency units that can represent thousands of different values. So, for example there might be coins worth 1c, 3c, 5c, 7c, 7.5c, 80c, 8001.5c etc. Given a list of ...
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2answers
131 views

Approach to coding algorithms to minimize rework [closed]

I find myself reworking my code quite a bit, especially when learning to write algorithms that involve keeping track of multiple attributes and labels. I feel that having the pseudo-code written up, ...
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2answers
307 views

Algorithm for detection of overlapping between vectors

I am currently developing a math-physics program and I need to calculate if two vectors overlap one another, the one is vertical and the other is horizontral. Is there any fast algorithm to do this ...
2
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1answer
376 views

How to Detect Sprites in a SpriteSheet?

I'm currently writing a Sprite Sheet Unpacker such as Alferds Spritesheet Unpacker. Now, before this is sent to gamedev, this isn't necessarily about games. I would like to know how to detect a sprite ...
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1answer
90 views

Applying the Art Gallery problem to optimal sensor placement

I am trying to design an algorithm for optimal sensor placement in a given area. After doing some research I found the Art Gallery Problem. However, this problem assumes that the guards can see all ...
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1answer
136 views

Memoization Memory

Memoization is definitely a powerful technique. But Dynamic Programming is slightly better IMO, since it does not involve the memory strain (in a recursive program, the parameters occupy memory and ...
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3answers
773 views

Apple eating problem

Player A and Player B play a game. On the middle of the table there is a pot full of N apples of different weights. Player A starts first and choose an apple and start eating it. Losing no time player ...
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0answers
83 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 ...
2
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1answer
134 views

Programming conundrum - most efficient path

I have a non-language-specific problem which I'm having trouble finding a workable answer for. I have a 10x10 grid containing integer values from 1-10. Each value represents the cost of travelling ...
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218 views

Coming up with a valid ranking algorithm for articles

I'm creating a website which will publish one or more articles a week. I'd like to be able to rank the articles based on popularity. In order to do this, I need a formula to calculate a score for ...
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2answers
423 views

How to draw a spiral using segments of varying circles?

I have an old plotter that can't handle printing true spirals. I need help with developing an algorithm to approximate a spiral. Here's a LISP sub-script that I have written which uses semicircles ...
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2answers
804 views

Is there any use for a smart algorithm developer who will delegate the coding?

In my job as an algorithms developer, I am responsible not only for developing algorithms, but also for implementing them, all the way down to writing the code that goes into production. I've heard ...
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209 views

Algorithm for searching images within images [closed]

I can't google this question, because I can't come up with a good query, so let me describe what I want and maybe someone will be able to suggest a way forward for me. I need to solve the following ...
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3answers
449 views

Is it better to use a switch statement or database to look through 5,000 to 10,000 instances?

I have some JSON data in this format (5,000 instances for now): {"id":"123456","icon":"icon.png","caseName":"name of case"} I am allowing the user to search for the name of the case and then return ...
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1answer
41 views

Given n distinct keys, how many different 2-3/Red-black trees can be constructed?

Memory refresher/My understanding: A 2-3 tree is a balanced search tree that allows two types of nodes. 2-node: Normal node with two children. LChild < Parent and RChild > Parent 3-node: ...
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4answers
439 views

Binary Search seems superior, why did the committee of C++ still have Find in the algorithm library?

I wish to search for an integer in a vector of integer. I have two candidates for the job: Binary Search Find It seems that Binary Search is the best candidate for the job as although I have to ...
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3answers
203 views

Sorting an array when values are decreased by each swap [closed]

Recently in an interview I come across a question: We have an unsorted array, we need to sort it with minimum number of swap. We have in sort a 'tax' of 1 is deducted from the number we are ...
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127 views

Storing simple / flexible pricing logic in the database

I am working on a pricing algorithm where I want to generalize the calculation of certain components/charges. There are 3 components to the charges. 1 - a basic/core charge, 2- a handling charge ...
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348 views

Find possible variations of one item out of multiple baskets.

I have three baskets of balls and each of them has 10 balls which have the following numbers: Basket 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Basket 2: 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ...
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Is Pre-Order traversal same as Depth First Search?

It seems to me like pre-order traversal and DFS are same as in both the cases we traverse from root till the left branch and back to root and then to the right branch recursively. Could any please ...
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1answer
645 views

What are the essential mathematics topics that a programmer should know in order to learn algorithms? [closed]

Being a electronics engineer, I was never exposed to any algorithms. Now I am a experienced programmer and want to learn Algorithms. I started with CLRS. But I was overwhelmed by the maths in the ...
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1answer
76 views

Even distribution through a chain of resources

I'm working on an algorithm which routes tasks through a chain of distributed resources based on a hash (or random number). For example, say you have 10 gateways into a service which distribute tasks ...
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1answer
62 views

Finding minimum path with return?

I'm having trouble understanding a past quiz question I got: Bobby works at Starbucks in San Mateo (V). He is doing quality assurance testing and needs to visit stores in Palo Alto (B), Tenderloin ...
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1answer
113 views

Need an optimization algorithm

I need this algorithm for one of my projects. I will paraphrase the problem. There are 'n' ropes that have different colored rings on them. (The colors might repeat on the same rope or across ...
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1answer
69 views

What algorithm pairs blocks so that the weighted average of the two blocks falls within an upper and lower bound?

What algorithm would pair parcels with a high proportion of property x to a parcel with a low proportion of property x so that the weighted average of the two parcels falls within an upper and lower ...
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Algorithm/research on detecting language of text [closed]

I am interested in finding an approach that will detect what language a string of text is. As Google translate does.
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4answers
419 views

difference between exponential and logarithmic growth

Why for(k=1;k<=n;k*=2) grows logarathmically = O(logn) but I feel it grows exponentially, as the seq look like 1,2,4,8.... and for fibonacci series people say it grows exponentially. which for me ...
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3answers
98 views

Detect Order Changes in a List

Let's say you have a list of values that are a b c d e The order on the list might be changed. a c d b e How would you detect this change? We needed something like this when we were ...
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2answers
99 views

How to limit time period to another period?

For a project planning I have an initial period, lets call it PPStart-PPEnd. The planning is associated with a project. This also has a period PrjStart-PrjEnd. PrjStart and PrjEnd are fixed, and can ...
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5answers
468 views

Which mathematical properties apply to XOR Swap algorithm (and similar bitwise operator algorithms)?

Assume you have two variables a and b, and you need to swap them, and for whatever reason, making a temporary variable for storage is not an option. This is the algorithm in pseudocode a ← a XOR b b ...
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1answer
102 views

Mapping values over a curve

I have a value between 0 and 8000 and I want this number to resolve to another number between 0 and 2000. I could just divide it by 4 but I have a special need here. For values above 4000 I want the ...
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5answers
250 views

Mapping 40 unique integers to 41 and back

This was a question proposed by a friend of mine. Define an algorithm that, given 40 unique integers in the range 1-1000, returns 41 unique integers in this range. Given these 41 integers, we must ...
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2answers
203 views

How to reduce close points

input: C matrix 2xN (2D points) output: C matrix 2xM (2D points) with equal or less points. Lets say we have C matrix 2xN that contains several 2D points, and it looks something like that: What we ...
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expressing the speed of a sorting algorithm

How would I express the speed of the following sort algorithm? I know bubblesort is n^n (er, I mean n^2...as someone pointed out below). In the following the array decreases each time you call it ...
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What is the purpose of chunking strings in natural language processing?

I see many examples of libraries that use a 'chunker' and also people asking how to write chunkers, but what is this for and why do we need it? Isn't it enough to split a text by whitespace or other ...