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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Shortest path to visit all nodes

I am given a set of tourist attractions(nodes identified by x, y) and i need to find the shortest path to visit them. The way i thought of it, is i will ignore if there are streets available and ...
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13 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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3answers
106 views

How to code a one-sided virtual economy

I'm attempting to make an online game with a mini-economy in it. The challenge is that the only person selling anything will be the website itself, and hence the supply and demand curve doesn't apply ...
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4answers
266 views

Application qos involving priority and bandwidth

Our manager wants us to do applicaiton qos which is quite different from the well-known system qos. We have many services of three types, they have priorites, the manager wants to suspend low priority ...
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3answers
196 views

Need help identifying a league scheduling algorithm

I am trying to create a sports league scheduler. I am having trouble identifying an algorithm to help me efficiently fill in each slot. Sample data to build the schedule would be: 10 teams Each ...
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0answers
46 views

Selling off an algorithm? Patent, copyright, attorneys… what do I do? [on hold]

I built this financial algorithm that solves a broad problem but has several elaborate modules executing it. I don't think there is anything like it out there and I think it may have lucrative ...
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3answers
168 views

How to do “image shifting” faster?

I have a grayscale matrix (implemented as a simple array) to be shown on a display: line 1: | a | b | c | line 2: | d | e | f | a-f are grayscale values. This pattern has to be shifted by a ...
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1answer
162 views

Algorithm for rating books: Relative perception

So I am developing this application for rating books (think like IMDB for books) using relational database. Problem statement : Let's say book "A" deserves 8.5 in absolute sense. In case if A is ...
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1answer
51 views

Algorithm to find the fewest number of values (from a set of values) where the sum equals a value (+ one more condition)

The simplest way to explain this is with an example. You're given then number 19 and you have a set of numbers to choose from: 1, 2, 3, 4, 6 When choosing values from the list (which can be ...
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4answers
1k views

How do you find the first common element in two arrays

The way I did it was to loop through each at the same time and add the current value to a separate set for each of the lists. Also, check if the current element is already in the other list's set. I ...
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0answers
31 views

Source of extensive, battle-tested Unit Tests [on hold]

Where can I find solid, proven unit tests for common data structures and algorithms? I'm giving an introductory class, that covers basics such as lists (linked, array-based, tree-based, etc.), ...
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6answers
4k views

Can we technically un-blur images?

Since there is an algorithm to blur images, so that part of it cannot be recognised, can we reverse the algorithm and unblur part of than image? Is there a program that already does that, is that ...
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31 views

Find the number of increasing Sequence of length K

Let we are giving a Array we have to find the number of increasing sequence of length K. 1 2 3 1 1 For the first window of [1, 2, 3], there are 3 non-decreasing subranges so the answer is 3. For ...
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6answers
2k views

How to turn truth table into smallest possible if / else block

How can I take a truth table and turn it into a compacted if block? For instance, let's say I have this truth table where A and B are conditions and x, y and z are possible actions: A B | x y z ...
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7answers
4k views

Is there any algorithm pattern to protect any content in the web to ensure I am the first one who created it?

A few years ago there was this hacker (don't remember who he was) that full disclosed a vulnerability in a given system, but to make sure nobody took credit for that, he created some kind of PGP key. ...
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24 views

Line wrapping with variable number of lines… almost there! [on hold]

I'm fiddling a way to split a string in a variable number of lines. It's working but I would like the lines to be a bit more even in size so that they take less space horizontally. I've been over it ...
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3answers
100 views

Concept for dealing with recurring appointments

Our company implemented a calendar system a few months back with recurring appointments, using iCal strings to store the recurring appointment criteria. We are starting to run into performance ...
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1answer
3k views

Shortest Common Superstring: find shortest string that contains all given string fragments

Given some string fragments, I would like to find the shortest possible single string ("output string") that contains all the fragments. Fragments can overlap each other in the output string. ...
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8answers
1k views

Is there a subset of programs that avoid the halting problem

I was just reading another explanation of the halting problem, and it got me thinking all the problems I've seen that are given as examples involve infinite sequences. But I never use infinite ...
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30 views

Algorithm for intersection of two convex polygons among set of m convex polygons in a plane

There are set of m convex polygons(p1, p2, p3…pm) in a plane. Pi contains ni number of vertices. All total n1+n2+…+nm=n vertices. Two convex polygons intersect if either their boundaries intersect or ...
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0answers
31 views

Merge directed acyclic graphs minimizing number of nodes

I have some DAGs (directed acylic graphs) and I want to merge them in order to minimize the number of nodes (we could say that every node has a cost, while edges are free). These four different DAGs ...
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0answers
42 views

How to print The sequence of numbers in structure array [closed]

I have the task which cannot be solved. My task is create a sequences of cards. How print my sequences ? i really need help. my solution #include <iostream> #include <fstream> #include ...
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3answers
173 views

Count unique visitors by group of visited places

I'm facing the problem of counting the unique visitors of groups of places. Here is the situation: I have visitors that can visit places. For example, that can be internet users visiting web pages, ...
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2answers
179 views

How are the tiles in WORDAMENT organized?

I'm trying to create a word game, just like WORDAMENT, in my spare time. In order to present a new round, I need to create a board with 16 letters organized in a 4*4 grid. Currently, I'm generating ...
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46 views

What are the Steps/Algorithm to load/Parse an XML File? [closed]

I want to write an xml parser by my own, its a project given to me, and i should complete it, i know to search for a string, load files into memory using vectors, but is theres a way i can use this to ...
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74 views

Permutting a list of numbers in order to get a list which satisfies given condition

Here is algorithmic problem I'm trying to solve: Given a list [x_1,x_2,...,x_n] return a permutation of elements of the list [y_1,y_2,...,y_n] (where for each i we have y_i = x_j for only one j) ...
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77 views

Divide an Array into n subarray such that each subarray have equal sum? [closed]

You are given an array of a given length. Now we have to determine whether we can Divide the array into n sub-array such that all of them have equal sum . Note: Each sub-array may or may not have ...
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77 views

RGB => HSL => hue range name conversion algorithm off by positive 60 degrees [migrated]

Background For practice (in ruby) I am implementing some color conversion algorithms. I have attempted to convert pseudocode avilable on EasyRGB.com to Ruby. The conversion seems to be working fine. ...
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1answer
143 views

Matching algorithms in context of data quality problems

I work for an organization that has lots of databases containing person information. The data quality is poor. One case was a surname I found like this (this is the worst-case scenario): Mark ...
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1answer
127 views

Finding all subsets of a set running time

Given a set {1,2,3} output { {}, {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3} } I have only been able to find as fast as O(2^n), is there any techniques for achieving faster results (besides ...
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23 views

Best way to aproach creating an MRP [closed]

Ive been ask if I could create an MRP (Material requirements planning) program, from what I have read its seems like a complex program manager, I've been working on it for a couple of days now, and ...
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2answers
87 views

Porting an algorithm implementation licensed under GNU GPL v3

I'm working on a JavaScript port of a red-black tree implementation in Java from the book Algorithms 4th Edition, by Sedgewick and Wayne. I believe that my JavaScript port qualifies as a derivative ...
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How to handle large numbers?

Well, I've just started doing puzzles and it's so annoying to see puzzles which are easy to do but also need to handle very large numbers. That's the problem. Say I have to deal with numbers like 10 ...
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1answer
67 views

Matrices calculations on partial shape matching

I'm working in a shape recognition project where it is supposed for me to develop an application that receives two images: an original one and a sketch made by a user. I am supposed to detect contours ...
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2answers
146 views

Finding common prefixes for a set of strings

I am trying to find common prefixes for a sorted set of strings. i.e. if the following strings are given: AB123456 AB123457 ABCDEFGH ABCDEFGX1 ABCDEFGY XXXX then my function should return three ...
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1answer
80 views

Easiest algorithm implementation of a game tree? [closed]

I want to create an algorithm to play out all possibilities in this game and print the most optimal moves. (This is a variant of mancala. You don't need to play the game to understand my code (the ...
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2answers
90 views

Track a series of choices with a single number

I want to track a series of scored questions in a single number (the total score). Is that possible? and how? For example, I have 30 questions with either 3 or 2 choices. For any given question, the ...
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49 views

Excel-like column numbering [migrated]

I have a working code (below) to convert a number to Excel-like (A...Z AA...AZ BA...BZ ...ZA-ZZ) column codes (headers). For simplicity I limited it to 1 or 2 character codes. My question is: ...
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1answer
179 views

How can I rank teams based off of head to head wins/losses

I'm trying to write an algorithm (specifically in Ruby) that will rank teams based on their record against each other. If a team A and team B have won the same amount of games against each other, then ...
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51 views

Test if a point is inside or outside a 3D polygon

I'm wondering if there is an algorithm (or a code written in FORTRAN) that gives whether a 3D point is inside or outside a polygon having triangles as faces (an .stl file from gmsh for example). Most ...
2
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1answer
117 views

moving around virtual keyboard

I'm creating virtual keyboard using javascript/html/css. And I can't find a good algorithm for moving from one button to another in different directions (top-bottom, left-right). Lets say I ...
2
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3answers
268 views

Best practices for geolocation

We are writing a flight search engine. We want to pre-fill the departure airport for mobile users with the closest one to their location. To do that, our plan is to Find a list of airports with ...
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1answer
77 views

saving connectivity information in a nodes/edges network

I want to implement the A* algorithm. I have a network with Nodes and Edges, both are classes. Now, I am unsure how to approach the connectivity information. Should a node know which edges depart ...
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1answer
92 views

How can I approach creating an efficient algorithm for maximizing value with these specific constraints?

I'm having trouble coming up with an approach that isn't n^2 for this problem. Here's a contrived, simplified version I've come up with: Let's say you're a company that needs 4 employees to launch in ...
7
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3answers
900 views

What is the Bible of Hashing?

Is there a Cormen-like reference on Hashes and Hashing? This particular structure has seen little attention in my CS education for some reason but I'd like to learn more as they seem to be everywhere. ...
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2answers
421 views

Kth Optimal path in a matrix

I had the following question I was trying to solve: You are given a n*n matrix. Every cell of the matrix contain some value (positive). You are currently at (0,0) and you have to go to right ...
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161 views

Karger's algorithm for bin-packing?

I first came across that algorithm as the "Random minimum cut" algorithm. And recently a colleague was trying to pack a big quantity of small textures into one image file. Then it clicked - why not ...
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1answer
176 views

Calculate reachability of one point from another

I have an array which stores a set of positive x coordinates in sorted way, say arr={1, 4, 5, 9, 12, 45} etc. And I have a maximum distance k which I can go from one point to another point let ...
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1answer
38 views

Min weight feedback edge set with DFS?

Exercise from The Algorithm Design Manual 6-10. [4] Let G = (V,E) be an undirected graph. A set F ⊆ E of edges is called a feedback-edge set if every cycle of G has at least one edge in F. ...
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85 views

Finding same numbers in a matrix

I have a question here and I am trying to find a solution of it. But I want to see some other opinions as well. The problem is the following: There is a matrix NxN which holds integer numbers. ...