A graph can refer to a graphic (such as a chart or diagram) showing or displaying the relationship between two or more variables used, for instance, in visualizing scientific data.
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votes
0answers
50 views
Topological Sort and Graphing in Python 3
I wrote a program for DFS traversal, topological sort, find all vertices, and has_cycle methods.
Can you please suggest more elegant and eloquent ways for this program?
(Perhaps better ways to ...
4
votes
1answer
67 views
Getting all likes from a specific user on a news wall with fewer graph API calls
Right now, my solution counting likes of a specific user is
Starting a recursive call on the "/{user-id}/posts" edge
Iterate through all posts
On each post iterate through each like on the likes ...
6
votes
1answer
127 views
Finding all paths from a given graph
I need to find all paths from a given graph. I can do that for now, however my recursive code is not efficient and my graphs are very complicated, hence I need a better algorithm.
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6
votes
1answer
55 views
Extracting nodes from a road network
My code takes 143.023 seconds for extracting nodes from a road network of city like Göteborg in Sweden. Please check it out if I can optimize it.
...
5
votes
0answers
71 views
Thinking in 'Haskell' - when to use (state) Monads
I really enjoy Haskell but feel I still have a total beginner's style, and would like to move beyond that. The code below - for Dijkstra's shortest path algorithm - is a case in point. I feel as ...
5
votes
1answer
66 views
Generic Graph Library Part 2 : Algorithms
(This is a follow on to this question).
Having given an implementation for some of the graph structures, here is a portion of the algorithms that are defined to work over them:
graph_degree.hpp
...
10
votes
1answer
98 views
Generic Graph Library
I've been working on a generic graph library for a while now, in a bit of an off and on fashion. I realise that boost::graph exists, but it is a complex library ...
3
votes
2answers
83 views
Simplify an if else construct with assignment before if and else
I want to simplify an if: .. else: .. construct:
...
2
votes
1answer
54 views
M coloring problem
Given an undirected graph and a number m, determine if the graph can be colored with at most m colors such that no two adjacent vertices of the graph are colored with same color. Here coloring of a ...
0
votes
2answers
69 views
Detect cycle in an undirected graph
This code detects cycle in acyclic graph. The assumption of this approach is that there are no parallel edges between any two vertices. Looking for code review, best practices and optimizations.
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2
votes
0answers
29 views
plotting many images at once in matplotlib
I am using numpy and matplotlib to do a statistical simulation. The simulation itself is pretty fast thanks to numPy vectorizatio, however the plotting is slow since I still use a for loop. Here is ...
4
votes
1answer
78 views
JFreeChart Dynamic Scatter Chart
I have a model that consists of a 100 'agents' that change their x and y coordinates randomly. I use JFreeChart scatter chart to represent agents' locations.
...
8
votes
2answers
308 views
Missing level of technical depth (Common Ancestor)
I recently have given a coding test in a reputable IT company. There were three coding questions.
They refused me by saying that
as we felt they didn't demonstrate the level of technical depth ...
6
votes
1answer
148 views
Escaping the prison - finding the shortest way
I have given an assignment where I have to escape a labyrinth. The goal is to find the shortest way. I have done some research and there seem to be two strategies to solve the problem: the Depth-first ...
7
votes
3answers
427 views
Depth First Traversal of a Graph
I am learning how to implement a basic undirected graph and perform a depth first traversal.
Please critique my code for correctness, best practices, security, and any other comments that may be ...
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vote
0answers
43 views
3
votes
4answers
4k views
Depth First Search & Breadth First Search implementation
I've implemented DFS and BFS implementations. I want to check if the code is readable, contains any issues, and can be improved.
GraphImplementation
...
3
votes
1answer
190 views
Tarjan's algorithm for Strongly Connected Components without keeping SCC in stack
I've been looking for an implementation of Tarjan's algorithm in C#/C++ for a strongly-connected components in graphs, and couldn't find any implementation without use of additional Stack - most of ...
2
votes
1answer
82 views
Lift ball which leads to shortest height
There are n balls kept on a table and connected by same singe connected string (which can be cyclic or maynot). Write the code to select a ball such that after lifting the whole structure from that ...
5
votes
1answer
79 views
Strongly connected components algorithm
In my Python application, I am using Tarjan's algorithm to compute strongly connected components. Unfortunately, it shows up under profiling as one of the top functions in my application (at least ...
6
votes
2answers
142 views
Clone of an undirected graph
Perform a graph clone. Verifying complexity to be O(E). Looking for code review, optimizations and best practices.
...
3
votes
1answer
74 views
Clone an undirected graph
I'm looking for code-review, optimization and best practices. Also verifying complexity to be O(E) time and O(V+E) space complexity.
...
6
votes
2answers
570 views
Ford-Fulkerson algorithm
Solved the ford-fulkerson algorithm, which is too vast to explain it comprehensively here. Check Wikipedia for Ford-Fulkerson and Princeton lecture on Ford-Fulkerson.
Looking for code review, ...
11
votes
3answers
2k views
Find all paths from source to destination
Given a directed connected graphs, find all paths from source to destination.
Looking for code review, optimizations and best practices. Also need help figuring out complexity, which in my best ...
1
vote
0answers
20 views
Completing a Graph in Scheme
For the record, this is part of a homework assignment, but I have already implemented a solution. I am simply wondering if there is a better way to do it.
Background: I am asked to write a procedure, ...
11
votes
1answer
1k views
Topological sort in Java
I am learning algorithms in graphs. I have implemented topological sort using Java. Kindly review my code and provide me with feedback.
...
0
votes
0answers
61 views
Iterative DFS algorithm
I've written an iterative version for DFS. For a quick overview of the benchmark results for a complete graph:
So it looks like it behaves within the boundaries of the theoretical complexity.
...
5
votes
2answers
236 views
Constraint Programming: Map color problem
I've written some python code to solve the map coloring problem. In my code, I represent the problem using Territory and ...
6
votes
1answer
156 views
Dijkstra-like routing algorithm
I've got the following code to find the shortest path between two nodes using almost-Dijkstra's-algorithm which was written for an exercise, and I'm looking for things to improve my general Scala ...
4
votes
1answer
55 views
Maximize the number of nodes that could be reachable in a graph
Description of my code:
I am trying to maximize the number of nodes that could be reachable in a graph. Please do not consider my main algorithm, I want it to be like that. The only parts that I need ...
4
votes
1answer
117 views
Modified BFS code optimizations
I need some help reviewing this code in terms of making as fast as possible. This is a modified version of BFS that does quite a bit of processing on the side.
Use case:
I have a large graph ...
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vote
0answers
76 views
Actionscript Graph data structure implementation
So, I am not sure if I should have Vertex extend Point, because the equals() and ...
1
vote
1answer
181 views
Automate a dependency graph with parallel programming [closed]
I found a C/Linux exercise in a book, and I propose a code as a solution, please feel free to correct it.
Here is the exercise :
Taking into consideration the following dependency graph, which ...
4
votes
1answer
324 views
Dijkstra's and Prim's algorithms: correctness/efficiency
This is in preparation for a competition that only allows C++03.
...
5
votes
1answer
192 views
Code to construct a complete graph
I have tried to design a class for a complete graph.
Needless to say, disadvantages of my current solution are very visible:
dependent inputs have led to verification headaches.
In this code we ...
9
votes
2answers
4k views
A* search algorithm
NodeData stores all information of the node needed by the AStar
algorithm. This information includes the value of ...
7
votes
2answers
1k views
Check if directed graph contains a cycle
I have solved the question, and in turn felt the need to get it reviewed. Any suggestions for clean up and optimization would help. Also please verify my complexity: \$O(V + E)\$.
...
3
votes
0answers
320 views
5
votes
1answer
2k views
Prims algorithm implementation
Review this code regarding optimization, cleanup, and best practices.
...
5
votes
2answers
7k views
Learning to code a graph
This is my first attempt at putting the conceptual knowledge I've gained about graphs into code. When searching for examples they all seem overly complicated, and searching for a tutorial or ...
5
votes
2answers
160 views
How to improve this algorithm for building a graphs closures
We have a large directed acyclic graph and a requirement to filter it by allowing a user to select certain nodes and then we remove all nodes that are not selected nodes, ancestors of those nodes, or ...
0
votes
1answer
121 views
Applying Dijkastra's algorithm on a graph of five nodes
Last week I posted a piece of code to apply Dijkastra algorithm to calculate the shortest path between to nodes in a graph. Now, I've made some improvements, but I am still having difficulties.
I ...
2
votes
1answer
3k views
Implementation of Prim's minimum spanning tree
Feel free to tell about every possible issue (style, errors, inffective solution etc.) you found. Here is the main part of what I want to be reviewed, through there is some related code on GitHub.
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2
votes
0answers
116 views
Evaluating code for a graph [closed]
This is relatively long code. Please take a look at this code if you are still willing to do so. I will appreciate your feedback.
I have spent two days trying to come up with code to represent a ...
1
vote
1answer
191 views
DFS algorithm with generators
Background:
I was working on a project were I needed to write some rules for text-processing. After working on this project for a couple of days and implementing some rules, I realized I needed to ...
3
votes
1answer
102 views
Review/rate my new graph class
I have written a PHP class called "graph". It is a class that performs RESTful-like commands to a MySQL database. I have posted the GitHub repo.
Here is the code as well:
config.php
...
5
votes
2answers
2k views
Implementation of Dijkstra's algorithm
Please pick my code apart and give me some feedback on how I could make it better or more simple.
...
1
vote
1answer
169 views
2003 Canadian Computing Competition, Stage 1 ; Why Is My Solution Invalid?
I am doing old versions of the Canadian Computing Competition, on a website where I can run my solution against some test cases they have. I am failing one of their test cases, and cannot figure out ...
6
votes
1answer
247 views
Shortest Path in a Unit Cost DAG BFS in Hadoop
Just got done implementing a shortest path algo of a unit cost DAG BFS in Hadoop and wanting to get anyone's opinion on how I could have done it better. The main issue I see is that I lose the ...
4
votes
1answer
747 views
Do I need to delete a vector?
I want to make a graph from input from a text file in the format:
vertex1 vertex2 cost time
where vertex1 and vertex2 are strings that form an edge and cost and ...
