a mathematical structure that contains a collection of vertices or 'nodes' and a collection of edges that connect pairs of vertices

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-1
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0answers
19 views

Overplotting the 6 plots by changing into 3 plots [on hold]

Two M-files one contains differential equations and another one to run and plot the graphs. since i am using ode solver, it has two files to run. % Creating recent original 3 ode without scaling any ...
1
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0answers
50 views

Simulation of a point mass in a box (3D space) [migrated]

I would like to simulate a point mass within a closed box. There is no friction and the point mass obeys the impact law. So there are only elastic collisions with the walls of the box. The output of ...
1
vote
1answer
35 views

Equidistant polygons

Consider these polygons: For reasons of simplicity I only consider triangles or polygons with 4 vertices. These shapes are specified by the vertices, the output of the program should be modified ...
0
votes
1answer
48 views

An algorithm for finding converse duplicates of ordered pairs

Given an array of ordered pairs of values, is there a well-known algorithm to find converse duplicates? [Converse meaning the same values, but in the opposite order.] That is, given ...
1
vote
0answers
61 views

Understanding Tarjan's Bridge-finding algorithm

Tarjan's algorithm for finding bridges in a graph is found here: http://en.wikipedia.org/wiki/Bridge_(graph_theory)#Tarjan.27s_Bridge-finding_algorithm. However, I don't understand the condition for ...
0
votes
1answer
31 views

Matching weighted unbalanced Bipartite graph

I am looking for a way to solve an assignment problem, but I am having some problems finding the correct algorithm to use. I have 2 list of nodes A and B, and in my problem may the length of A not be ...
2
votes
1answer
101 views

Improving the running time of Breadth First Search and Adjacency List creation

We are given an array of integers where all elements are between 0-9. have to start from the 1st position and reach end in minimum no of moves such that we can from an index i move 1 position back and ...
1
vote
1answer
120 views

How to canonise a road network

I am working on geographical data which represents the road network of some city and I need to automatically fix inaccuracies in the data. Data was manually produced by “drawing” the road network ...
2
votes
1answer
75 views

Maze generation given intersection tree

Background Information: I'm building a 2D maze generator. I have tried Prim's algorithm, Wilson's algorithm, and a recursive backtracker algorithm for generating my maze, however was not satisfied ...
0
votes
0answers
34 views

Charts, SQL and REST?

We have created a REST API for a voting game. Now we are jumping into creating analytics/graphs/charts for moderators and users to watch how are they doing in the game. The game has a certain group ...
0
votes
1answer
130 views

Euclidean Space Fully Connected Nondirectional Graph: Shortest Path to all nodes

So this may be a question that is born of my inability to properly express my intentions to Google. In a fully connected non-directional graph such that any three points can be properly represented ...
3
votes
2answers
255 views

How to find number of points with same minimal distances on matrix

I'm trying to find the number of points in a matrix with the same minimal distances. Start with a MxN matrix, where M and N < 50000. There is given a set of fixed points, with their respective ...
6
votes
1answer
155 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 ...
5
votes
5answers
415 views

Finding most Important Node(s) in a Directed Graph

I have a large (≈ 20 million nodes) directed Graph with in-edges & out-edges. I want to figure out which parts of of the graph deserve the most attention. Often most of the graph is boring, or at ...
1
vote
1answer
119 views

Question on Graph

I am trying to implement a graph data structure in C#. I have the following interfaces: public interface IVertex<TValue> { TValue Value { get;} ...
1
vote
2answers
122 views

Algorithm for defragmenting cross-pipe issues in a network for routing signals through?

I have a network I'm responsible for routing signals through. You can think of the network as a directed graph of nodes (hardware) but each edge is really a pipe capable of fitting a specific ...
0
votes
2answers
128 views

What algorithm should I use to find the shortest path in this graph

I have a problem about the calculation of shortest paths on an unweighted and undirected graph. Which algorithm I use to calculate the shortest path between a node A and node B that passing through a ...
0
votes
1answer
182 views

Weight-maximizing (weighted vertices) path algorithm

I am looking for description (name of algorithm, code, pseudocode, etc.) that can help me frame this problem and find the appropriate recursion and the most efficient solution. Problem: Given a ...
0
votes
2answers
293 views

What graph traversal algorithm should I use?

I would like to write an algorithm which can traverse a graph and hopefully later I can implement it to use for an indoor navigation system. The graph would come from floor plans of a building and ...
4
votes
3answers
340 views

Optimal “if-else” tree algorithm to minimize duplicate code

I'm having trouble formulating this problem as an algorithm: I have a set of conditionals (combined with &&) and operations, for example: if (A && B) execute C else if (D ...
1
vote
0answers
74 views

Representation of time expanded graph

I want to build a time expanded graph with time discretization Dt that starts at t = 0 and ends at t = T where between the node (n1, t) and the node (n2, t') is an arc if and only if (n1, n2) were ...
0
votes
0answers
54 views

using internal or external iterators over graph edges

I've written some code to manipulate sparse graphs for school work I'm doing, and I have an operation which requires me to loop over all the edges of a graph. The interface I need to implement is some ...
3
votes
1answer
199 views

How to solve binary labeling with graph cut?

Many literature references suggest that the binary labeling problem can be converted into a graph cut problem and solved with the max flow/min cut algorithm. I'm trying to understand the formulation ...
1
vote
1answer
85 views

How can I find all connections in a mesh network/graph?

Suppose I have a mesh of relationships, such as Friends who trust some friends and not others A IPv6 router that needs to locate peers across the Internet A PGP Web Of Trust that needs two people ...
3
votes
2answers
377 views

Breadth-first graph search problem

I thought I was doing breadth-first graph search correctly, but my instructor's grading script is telling me that my answer is incorrect. From the instructions: Consider a breadth-first graph ...
1
vote
3answers
147 views

Storing a drawn graph information in database for web application

Well while developing a web application that allow users to draw graphs (flow charts, ER diagram , UML, .... etc) the information of drawn items and their relation to each other and position on canvas ...
2
votes
2answers
271 views

Is it possible to represent mutation of object-graph efficiently with immutable states?

I am practicing using of immutable object in C++. My personal goal is representing generic object graph (in heap) with sequence of immutable graphs. Building the multi-version graph itself isn't that ...
0
votes
2answers
211 views

Data structure theory based on graph rewriting [closed]

First of all, I'm looking for a book, publication, project or any kind of information that should probably exceed the limits normally imposed on answers in this kind of forum. I know the rules about ...
4
votes
1answer
160 views

Class instance clustering in object reference graph for multi-entries serialization

My question is on the best way to cluster a graph of class instances around specifically marked objects (objects are the graph nodes and the references to each other are the directed edges of the ...
1
vote
1answer
212 views

Connected components of a graph using Prolog

Given a corner x of an undirected Graph G I would like to ask for the connected component of x, but my first try does not work as desired. Here it is: edge( a,b ). edge( b,a ). edge( b,c ). edge( ...
2
votes
1answer
189 views

Algorithm in undirected BFS graph

I'm trying to put together an algorithm that will display the node degree for every node in a breadth first tree graph (assume BFS was called). Assume it's an undirected graph. I'm not sure how to ...
4
votes
2answers
97 views

Placing elements in graph with a streaming/online algorthm

We have a stream of points with about 1000 points per second. For each point, we have a complex vector (hundreds of dimensions). Our goal, for each point is to link it to the 5 closest points that ...
6
votes
1answer
492 views

Where to learn graph theory applications [closed]

I am completely new to designing algorithms with graphs. I am following CLRS and other video lectures in Youtube, notably from IIT/MIT. They are pretty good, and I currently have decent idea about ...
4
votes
1answer
827 views

Building a Graph Editor - How to create a data driven graph

I am developing a graph-editor that uses drag and drop to build hierarchical graphs (containing nodes and links). Each node in the graph should be linked to a table in our database (SQL Server). I did ...
1
vote
1answer
282 views

Languages with graph data structures and algorithms in standard library

I am trying to improve my knowledge and ability with graphs and graph algorithms and have noticed something curious: as far as I can tell no "mainstream" language contains support for graphs in its ...
2
votes
3answers
668 views

How can you prove an acyclic graph has n-1 edges? [closed]

I'm not so hot on the maths for this but for what I understand... A graph g exists with v vertices and edges. g = (V,E); The spanning graph for this is an acyclic copy of this where all the vertices ...
6
votes
1answer
127 views

Detecting areas of isotropic vs anisotropic diffusion in a flood-fill (or similar) operation

Hello fellow programmers! I have a 2D graph which is best described as a Cartesian grid with traversible and non-traversible cells. I'd like to be able to detect subsets of this graph where the ...
6
votes
3answers
1k views

What algorithm should I use to find the shortest path in this graph?

I have a graph with about a billion vertices, each of which is connected to about 100 other vertices at random. I want to find the length of the shortest path between two points. I don't care about ...
-2
votes
1answer
519 views

using ant colony algorithm to create cross word game [closed]

I have difficulty to learn about ant colony algorithm (ACO), I have read about generating crossword game using (genetic algorithm) GA.I Know both of GA ant ACO usually used for optimization, but my ...
0
votes
1answer
296 views

How to turn a website into an offline usable directed graph for searching shortest ways between pages [closed]

I am an advanced-intermediate level student focused on the .NET and C#. I know all the basics as well as classes, methods, objects, inheritance, OOP principles and all that. Problem is we haven't ...
18
votes
6answers
609 views

Visiting points on a number line while minimizing a cost not related to distance

I need some help on this ACM ICPC problem. My current idea is to model this as a shortest path problem, which is described under the problem statement. Problem There are N = 1000 nuclear waste ...
2
votes
1answer
342 views

Finding subtree in a tree

I have a tree: a / \ b c / \ d f / \ g h And the pattern: x / \ y z / \ q p As output I would like to have: x: a y: b z: c q: d p: f and x: b y: f z: c q: ...
6
votes
2answers
135 views

spotting graph cycles - simple explanation

could some please help me understand how to find cycles in graphs in laymans terms? I have read other questions, such as This one and also some of the wikipedia pages, but they seem to descend rather ...
1
vote
2answers
806 views

What is the best way to plot 3D/2D plots with real time data? [closed]

First of all, I like to use Python, because it is easy to work with. I am not a programmer, so I prefer anything that is easy to use and understand. I understand that it might be faster to program 3D ...
1
vote
1answer
157 views

Implementing a sort of navigation system

So I am undertaking a project which does navigation sort of thing. So here is how the problem statement looks like. Say, given a map of a floor, with different rooms, now somehow, this information is ...
6
votes
3answers
1k views

Cyclomatic complexity with two IFs - why it is 3?

I have read an article with following example: void func() { if (condition1) a = a + 1; if (condition2) a = a - 1; } It says the CC is 3 as there are three possible paths. How come? Why not 4? I ...
3
votes
2answers
230 views

Chambers In A Castle Algorithm

Problem Statement - Given a NxM grid of 1s & 0s (1s mark walls, while 0s indicate empty chambers), the task is to identify the number of chambers & the size of the largest. And just to ...
1
vote
2answers
900 views

Tree vs Graphs in search

Could anyone give a clear and concise explanation for when you use graphs vs when to use trees for data structures?
30
votes
7answers
6k views

When to use DAG (Directed Acyclic Graph) in programming?

I recently found a framework named ecto. In this framework, a basic component named "plasm", which is the ecto Directed Acyclic Graph.In ecto, plasm can be operated by ecto scheduler. I am ...
5
votes
4answers
1k views

What are graphs in laymen's terms

What are graphs, in computer science, and what are they used for? In laymen's terms preferably. I have read the definition on Wikipedia: In computer science, a graph is an abstract data type ...