graph.algorithm.KruskalMSTAlgorithm Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of astra-compiler Show documentation

Core compiler artifact for the ASTRA Language

The newest version!

package graph.algorithm;

import graph.core.AbstractGraphAlgorithm;
import graph.core.Edge;
import graph.core.Graph;
import graph.core.Vertex;
import graph.gui.GraphOverlay;
import graph.util.LinkedList;
import graph.util.Heap;
import graph.util.List;
import graph.util.PriorityQueue;

import java.awt.Color;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class KruskalMSTAlgorithm extends AbstractGraphAlgorithm {
	@SuppressWarnings("rawtypes")
	private class KruskalMSTOverlay implements GraphOverlay {
		@Override
		public Color edgeColor(Edge edge) {
			for (Edge e: T) {
				if (e.equals(edge)) return Color.RED;
			}
			return Color.BLACK;
		}

		@Override
		public Color vertexColor(Vertex vertex) {
			return Color.RED;
		}
	}
	
	private Graph G;
	private List> T;
	private Map, List>> cloudMap;
	private PriorityQueue> Q;
	
	public KruskalMSTAlgorithm() {
		super();
	}
	
	public KruskalMSTAlgorithm(Graph graph) {
		this();
		G = graph;
	}
	
	public void setGraph(Graph graph) {
		G = graph;
	}
	
	public void search(Map> parameters) {
		T = new LinkedList>();
		cloudMap = new HashMap, List>>();
		Q = new Heap>();
		for (Vertex vertex: G.vertices()) {
			List> list = new LinkedList>();
			list.insertLast(vertex);
			cloudMap.put(vertex, list);
		}
		
		for (Edge edge : G.edges()) {
			Q.insert(Integer.parseInt(edge.toString()), edge);
		}
		
		int n = G.vertices().size();

		while (T.size() < n - 1) {
			Edge e = Q.remove();
			Vertex[] endpoints = G.endVertices(e);
			if (!cloudMap.get(endpoints[0]).equals(cloudMap.get(endpoints[1]))) {
				T.insertLast(e);
				Iterator> it = cloudMap.get(endpoints[1]).iterator();
				while (!it.hasNext()) {
					cloudMap.get(endpoints[0]).insertLast(it.next());
				}
				cloudMap.put(endpoints[1], cloudMap.get(endpoints[0]));
			}
		}
	}
	
	@Override
	public GraphOverlay getOverlay() {
		return new KruskalMSTOverlay();
	}
}