Thursday, December 5, 2024

Max_Fun

 Why keep all the fun to myself. I asked Copilot for a harder max-cut problem

to work on, just to make sure I am getting the notion right. Below:


mathematics; could I see a difficult max-cut problem?

Sure! Here's an example of a moathemare challenging Max-Cut problem:


Problem Description

Consider a graph with 8 vertices and 14 edges. The vertices are labeled from 0 to 7, and the edges are as follows:

(0, 1), (0, 2), (0, 3), (1, 2), (1, 4), (2, 5), (3, 6), (4, 5), (4, 7), (5, 6), (5, 7), (6, 7), (1, 6), (2, 7)

Objective

Partition the vertices into two sets, S and T, such that the number of edges between the sets is maximized.

Solution Approach

Graph Representation: Visualize the graph with the given vertices and edges.

Initial Partition: Start with an initial random partition of the vertices into two sets.

terative Improvement: Use an algorithm like the Kernighan-Lin algorithm to iteratively improve the partition by swapping vertices between the sets to increase the number of edges crossing the partition.

Maximize the Cut: Continue the process until no further improvement can be made.

Example Solution

After applying the algorithm, one possible partition could be:

Set S: {0, 1, 4, 5}

Set T: {2, 3, 6, 7}

In this partition, the edges crossing the partition are:

(0, 2), (0, 3), (1, 2), (1, 6), (2, 5), (3, 6), (4, 7), (5, 6), (5, 7), (2, 7)

This results in a maximum cut with 10 edges crossing the partition.

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To accomplish step 1, ie getting a visual representation of the problem, ended

up asking Meta for python code to do this. I needed to install networkx (with conda)

and did so.

That's it so far. I do know the Kernighan-Lin algorithm is available

in the package...

                                                                 


*      *     *


                                                                          *     *     *

Finally, settled on ChatGPT code:
                                                           







                                                                          












           











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