graph-theory

I'm not sure exactly sure what the correct terminology is for my question so I'll just explain what I want to do. I have a directed graph and after I delete a node I want all independently related nodes to be removed as well. Here's an example: Say, I delete node '11', I want node '2' to be deleted as well(and in my own example, they'll be nodes under 2 that will now have to be deleted as well) because its not connected to the main graph anymore. Note, that node '9' or '10' should not be deleted because node '8' and '3' connect to them still. I'm using the python library networkx. I searched

Given an undirected graph in which each node has a Cartesian coordinate in space that has the general shape of a tree, is there an algorithm to convert the graph into a tree, and find the appropriate root node? Note that our definition of a "tree" requires that branches do not diverge from parent nodes at acute angles. See the example graphs below. How do we find the red node? collapsar here is a suggestion on how to solve your problem. prerequisites notation: g graph, g.v graph vertices v,w,z : individual vertices e : individual edge n : number of vertices any combination of an undirected

Lets say you have a circle (like below) with N spots, and you have N beads distributed in the slots. Here's an example: Each bead can be moved clockwise for X slots, which costs X^2 dollars. Your goal is to end up with one bead in each slot. What is the minimum amount of money you have to spend to achieve this task? More interesting variation of this problem: Algorithm for distributing beads puzzle (2)? In this answer I assume beads can only be moved once. Otherwise it would be evident that beads should only move one square at a time, which makes this problem much less interesting: the sum of

Disclaimer: I'm a total newbie at graph theory and I'm not sure if this belongs on SO, Math SE, etc. Given 2 adjacency matrices A and B, how can I determine if A and B are isomorphic. For example, A and B which are not isomorphic and C and D which are isomorphic. A = [ 0 1 0 0 1 1 B = [ 0 1 1 0 0 0 1 0 1 0 0 1 1 0 1 1 0 0 0 1 0 1 0 0 1 1 0 1 1 0 0 0 1 0 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 0 1 0 0 1 1 1 0 0 1 0 ] 0 0 0 1 1 0 ] C = [ 0 1 0 1 0 1 D = [ 0 1 0 1 1 0 1 0 1 0 0 1 1 0 1 0 1 0 0 1 0 1 1 0 0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 0 0 1 0 0 1 1 0 1 1 1 0 0 0 1 1 1 0 0 1 0 ] 0 0 1 1 1 0 ] (sorry for this

I'm looking for an algorithm to find an Euler path in a graph. I've seen a good one a couple of weeks ago but I can't find it now, I remember there was tagging edges, something with even/odd connections... Do you know a similar, simple and straightforward algorithm? MJW From Graph-Magics.com , for an undirected graph, this will give you the tour in reverse order, i.e. from the end vertex to the start vertex: Start with an empty stack and an empty circuit (eulerian path). If all vertices have even degree: choose any of them. This will be the current vertex. If there are exactly 2 vertices