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 to know whether to create a general system or to hack a solution

I'm new to coding , learning it since last year actually. One of my worst habits is the following: Often I'm trying to create a solution that is too big , too complex and doesn't achieve what needs ...
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1answer
83 views

Finding “spare time” in a day from within a list of events

I have a list of events which is always sorted chronologically. The start time is always followed by the end time. Times are strings formatted as 'HHmmss'. // list of events var events = [ ...
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149 views

Ranking players depending on decision making during a game

How would I go about a ranking system for players that play a game? Basically, looking at video games, players throughout the game make critical decisions that ultimately impact the end game result. ...
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2answers
109 views

How can I find the shortest path between two subgraphs of a larger graph?

I'm working with a weighted, undirected multigraph (loops not permitted; most node connections have multiplicity 1; a few node connections have multiplicity 2). I need to find the shortest path ...
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67 views

Looking for an algorithm to connect dots - shortest route

I have written a program to solve a special puzzle, but now I'm kind of stuck at the following problem: I have about 3200 points/nodes/dots. Each of these points is connected to a few other points ...
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1answer
78 views

Performing a Depth First Search iteratively using async/parallel processing?

Here is a method that does a DFS search and returns a list of all items given a top level item id. How could I modify this to take advantage of parallel processing? Currently, the call to get the sub ...
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3answers
84 views

Finding the shortest path through a digraph that visits all nodes

I am trying to find the shortest possible path that visits every node through a graph (a node may be visited more than once, the solution may pick any node as the starting node.). The graph is ...
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3answers
236 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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2answers
69 views

An algorithm for finding subset matching criteria?

I recently came up with a problem which I would like to share some thoughts about with someone on this forum. This relates to finding a subset. In reality it is more complicated, but I tried to ...
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1answer
90 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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2answers
68 views

Need to organize words based on their components, any other way aside from brute force?

I'm not sure if this process has a name. I have some words (about 9,000). They are in Japanese, but I'll try to explain this using English words. I want to categorize the words by the components (in ...
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2answers
723 views

Reverse horizontal and vertical for a HTML table

There is a two-dimensional array describing a HTML table. Each element of the array consists of: the cell content rowspan colspan Every row of this two dimensional array corresponds to <td> ...
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2answers
74 views

Can this word search algorithm be made faster? [closed]

Problem: Find a match of word S in text T Given: S and T are part of spoken and written English. Example: Match 'Math' in 'I love Mathematics' NOTE: Ignore CASES. My algorithm: STEP 1) Convert S, ...
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2answers
108 views

How to avoid or minimise use of check/conditional statement in my scenario?

I have scenario, where I got stream and I need to check for some value. If I got any new value I have to store it in any of data structure. It seems very easy, I can place conditional statement ...
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0answers
51 views

Approach for packing 2D shapes while minimizing total enclosing area

Not sure on my tags for this question, but in short .... I need to solve a problem of packing industrial parts into crates while minimizing total containing area. These parts are motors, or pumps, ...
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8answers
888 views

How meaningful is the Big-O time complexity of an algorithm?

Programmers often talk about the time complexity of an algorithm, e.g. O(log n) or O(n^2). Time complexity classifications are made as the input size goes to infinity, but ironically infinite input ...
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1k views

single for-loop runtime explanation problem

I am analyzing some running times of different for-loops, and as I'm getting more knowledge, I'm curious to understand this problem which I have still yet to find out. I have this exercise called "How ...
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1answer
114 views

Asymptotic running time of for-loops

I have this question which I need answered: What is the asymptotic running time for the following piece of code? if (N < 1000) for (int i = 0; i < N; i++) for (int j = 0; j < N; ...
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2answers
51 views

Know executables files launched/loaded by an executable file [closed]

I would like to know any executable files launched or loaded by an executable file (if possible without running it,if it is not possible i don't want any change in the system). For example i have ...
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2answers
162 views

Running time of simple for-loops

I'm reading algorithms and I understand most of it, one thing that I can still struggle with a lot is something as simple as running times on different for-loops. Everyone seems to have easy with ...
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1answer
87 views

JS design pattern/algorithm for avoiding duplicate redraws in a fairly coupled system

Given: some sort of widget based web app lots of JS functionality high coupling (communication/callbacks between widgets) widgets draw themselves certain widgets need to do a complete and fairly ...
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1answer
55 views

Dual pivot quicksort in face of expensive swaps

I was told this is better place to ask this TLDR Has anyone tested dual pivot quicksort performance with expensive-to-swap elements? It seems that in this case, it should massively underperform ...
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37 views

Crowd movements with Python [migrated]

I've done a program in order to calculate the time required to evacuate a room. The program takes in arguments the number of people (N), the dimensions of the room (L,l), and the location of the exit ...
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122 views

Level order sorted binary tree from a binary tree

Lets suppose we have a binary tree . Tree node structure is as struct node { int val ; struct node *left , *right ; } Now we have to sort the tree in level order manner . For example lets ...
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280 views

Pseudocode for Appel's algorithm implementation

I'm trying to implement the version of Appel's algorithm for vector hidden line removal (i.e. I'd like to avoid any form of rasterization). I found the description of this algorithm here - ...
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1answer
110 views

Calculate Pi to N number of places [closed]

I am trying to work out how to calculate Pi to N decimal places, I think the default DP's for a float/double is 5 and then you have setprecision() however these are obviously inadequate, I need ...
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1answer
61 views

How to chain together points in an array

I have a series of points with lengths and rotations like this: I need to create separate chains from points whose lines overlap but I’m having real trouble doing this efficiently. I have an array ...
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3answers
272 views

Quickly compute added and removed lines

I'm trying to compare two text files. I want to compute how many lines were added and removed. Basically what git diff --stat is doing. Bonus points for not having to store the entire file contents in ...
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1answer
75 views

Confusion in understanding the theorem on Amortization

I was reading a book on Algorithm Analysis by Micheal T Goodrich. I came across amortization technique and I got struck in understanding the proof of theorem. I am putting the theorem and the proof ...
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2answers
68 views

Creating fast, realtime dialogue search for television scripts

We have a database of television scripts and we'd like to search it, getting results as we type. We often remember words or snippets of dialogue but can't remember exactly what was said or what ...
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2answers
74 views

Distribute load evenly across many cycles

I am looking for a solution that is fast and still readable. I have to do this in C but the code will be static in the end, which mean I could use any tool to generate it. I have a task which runs ...
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38 views

Find common ancestor

Given X number of leaves (the ringed leaves in the picture) in an unbalanced tree with depth aroun 100-1000 and total number of nodes around 15 000 000. I'm looking for the first common ancestor for ...
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35 views

Stable, Hash Based Symmetrical Difference

A lot of thought went into the implementation of the set algorithms in LINQ: Distinct, Except, Intersect and Union. They guarantee that the items are returned in the same order that they appear in ...
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3answers
615 views

What function or method can I use to equally distribute a workload

This is more of mathematical question than an algorithmic one; nevertheless it will be implemented in php. I have an array of N tasks. Each task has taken t time to complete(e.g. task 1 has taken 5 ...
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3answers
124 views

Tournament bracket method to put distance between teammates

I am using a proper binary tree to simulate a tournament bracket. It's preferred any competitors in the bracket that are teammates don't meet each other until the later rounds. What is an efficient ...
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4answers
843 views

Architecture strategies for a complex competition scoring system

Competition description: There are about 10 teams competing against each other over a 6-week period. Each team's total score (out of a 1000 total available points) is based on the total of its ...
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0answers
74 views

Distributing Contestant Entries Between Multiple Bins, Is this Knapsack?

I am an algorithm novice and am faced with a rather difficult problem. I am working with contests. There are contestant - individual player entry - contestants can have multiple entries into a ...
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1answer
76 views

Notation/Meta Language To Express An Algorithm

I need to learn a notational language, so I can express and possibly prove the correctness of what I believe to be a complicated algorithm that distributes a credit adjustment across multiple water ...
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1answer
75 views

How to define the motion path of one object on a surface of the other one?

I have an uncommon problem. There are 2 3D objects, which are represented by arrays of vertices and triangles (.stl files). Each of them contains a big enough amount of vertices: 1-10 mln ones. The ...
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0answers
112 views

Frog crossing N lane road problem [closed]

Problem says that: There are N lanes, and the speed of each lane is given. There are many cars in all the lanes and the start position and the length of each car and its corresponding lane is ...
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1answer
93 views

What algorithms would suit image colour summarization?

I would like to analyse a set of hundreds of thousands of product images (clothing, electronic goods etc) and retrieve the dominant colours in each. I'm only interested in the top 3 or 4 colours. The ...
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1answer
112 views

Programming a promotions engine [closed]

I am trying to implement a promotions engine for an e-commerce application and I want to figure out how such engines work especially in situations like the following. Buy X Items from Category A ...
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2answers
218 views

Which algorithm is faster? [closed]

I'm creating a small game, where the computer generate pseudo random number in give range, and the user have to guess it. I also made the option to play computer vs computer. I mean the computer ...
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1answer
117 views

Optimal movie schedule

Let's say Mr. A goes to cinema and he gets a movie schedule. There are N movies on the program today (1 < N < 50) and for every movie the time of the start and the time of the end are given in ...
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2answers
208 views

An algorithm for a synchronization

I want to make a synchronization. What's the algorithm for it in a nutshell? 1) A client reads a local data and sends them to a server afterwards. The server compares them with its actual data, ...
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1answer
626 views

I know JavaScript really well, but i bomb coding interviews [closed]

So I'm currently on a hunt for a new position as a Front-End Developer. I know JavaScript very well and can wax poetically about Closures, Currying, Prototypal Inheritance, Design Patterns, App ...
4
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3answers
213 views

Accurate calculation of a raster image's boundary length

I have a rasterized image that contains two colors: white and black. The black portion is entirely connected and looks like a big blob. Is there a good way to estimate the length of the boundary ...
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2answers
83 views

Algorithm to reverse engineer permutation [closed]

I have a sequence of permutations formed using these strings: "A", "BC" and "D". The permutations are: BCAD ABCD BCDA DABC ADBC DBCA Now I need to reverse engineer this; i.e. I have a text file ...
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423 views

The physical implementation of quantum annealing algorithm

From that question about differences between Quantum annealing and simulated annealing, we found (in comments to answer) that physical implementation of quantum annealing exists (D-Wave quantum ...
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1answer
124 views

How to create an algorithm for determining Boolean Tautologies

So i am right now exploring some topics in a proof course and it occurred to me to try to create a boolean tautology solver. I would like an algorithm that is more efficient than brute force. Problem ...