graph-theory

问题 I made relation graph two relationship, like if A knows B then B knows A, Every node has unique Id and Name along with other properties.. So my graph looks like if I trigger a simple query MATCH (p1:SearchableNode {name: "Ishaan"}), (p2:SearchableNode {name: "Garima"}),path = (p1)-[:NAVIGATE_TO*]-(p2) RETURN path it did not give any response and consumes 100% CPU and RAM of the machine. UPDATED As I read though posts and from comments on this post I simplified the model and relationship. Now

问题 I need an example of the shortest path of a directed cyclic graph from one node (it should reach to all nodes of the graph from a node that will be the input). Please if there is an example, I need it in C++, or the algorithm. 回答1: EDIT: Oops, misread the question. Thanks @jfclavette for picking this up. Old answer is at the end. The problem you're trying to solve is called the Travelling salesman problem. There are many potential solutions, but it's NP-complete so you won't be able to solve

问题 Given a directed, connected graph with only positive edge weights, are there faster algorithms for finding the shortest path between two vertices, than Dijkstra using a fibonacci heap? Wikipedia says, that Dijkstra is in O(|E| + |V| * log(|V|)) (using a fibonacci heap). I'm not looking for optimizations that, for example, half the execution time, but rather algorithms that are in a different time complexity (like going from O(n * log n) to O(n)). Further, I would like to know your opinion on

问题 Here is a problem from Algorithms book by Vazirani The input to this problem is a tree T with integer weights on the edges. The weights may be negative, zero, or positive. Give a linear time algorithm to find the shortest simple path in T. The length of a path is the sum of the weights of the edges in the path. A path is simple if no vertex is repeated. Note that the endpoints of the path are unconstrained. HINT: This is very similar to the problem of finding the largest independent set in a

问题 I have an undirected graph with Vertex V and Edge E . I am looking for an algorithm to identify all the cycle bases in that graph. I think Tarjans algorithm is a good start. But the reference I have is about finding all of the cycles , not cycle base ( which, by definition is the cycle that cannot be constructed by union of other cycles). For example, take a look at the below graph: So, an algorithm would be helpful. If there is an existing implementation (preferably in C#), it's even better!

问题 I would like to draw a circular graph of nodes where certain nodes have a link between them. Here are a few examples from social network graphs: (source: wrightresult.com) (source: twit88.com) How can this be done with MATLAB? Is it possible without installing a separate package? 回答1: Here is one way you can do what you want. First, generate points on the circle that you are interested in clear; theta=linspace(0,2*pi,31);theta=theta(1:end-1); [x,y]=pol2cart(theta,1); Next, if you know the

问题 I'm wondering if anyone can recommend a good C++ tree implementation, hopefully one that is stl compatible if at all possible. For the record, I've written tree algorithms many times before, and I know it can be fun, but I want to be pragmatic and lazy if at all possible. So an actual link to a working solution is the goal here. Note: I'm looking for a generic tree, not a balanced tree or a map/set, the structure itself and the connectivity of the tree is important in this case, not only the

问题 I've been using a little python script I wrote to manage debt amongst my roommates. It works, but there are some missing features, one of which is simplifying unnecessarily complicated debt structures. For example, if the following weighted directed graph represents some people and the arrows represent debts between them (Alice owes Bob $20 and Charlie $5, Bob owes Charlie $10, etc.): It is clear that this graph should be simplified to the following graph: There's no sense in $10 making its

问题 I have a matrix A in Matlab of dimension mx2 that contains in each row the labels of two nodes showing a direct link in a network, e.g.: if the network has 4 nodes the matrix A could be A=[1 2; 1 3; 2 1; 2 4; 3 2; 4 1; 4 2] , where the first row means that there is a link from 1 to 2 , the second row means that there is a link from 1 to 3 , etc. Could you suggest me a quick way to draw the network from A? 回答1: If you want the links to be directional, and have the Bioinformatics toolbox, you

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . Anyone know where I can obtain a sample implementation of a Directed Graph and sample code for performing a topological sort on a directed graph? (preferably in Java) 回答1: Here is a simple implementation of the first algorithm from the Wikipedia page on Topological Sort: import java.util.ArrayList; import java