org.jgrapht.generate.CompleteBipartiteGraphGenerator Maven / Gradle / Ivy
/* ==========================================
* JGraphT : a free Java graph-theory library
* ==========================================
*
* Project Info: http://jgrapht.sourceforge.net/
* Project Creator: Barak Naveh (http://sourceforge.net/users/barak_naveh)
*
* (C) Copyright 2003-2008, by Barak Naveh and Contributors.
*
* This program and the accompanying materials are dual-licensed under
* either
*
* (a) the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation, or (at your option) any
* later version.
*
* or (per the licensee's choosing)
*
* (b) the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation.
*/
/* -------------------
* CompleteBipartiteGraphGenerator.java
* -------------------
* (C) Copyright 2008-2008, by Andrew Newell and Contributors.
*
* Original Author: Andrew Newell
* Contributor(s): -
*
* $Id$
*
* Changes
* -------
* 24-Dec-2008 : Initial revision (AN);
*
*/
package org.jgrapht.generate;
import java.util.*;
import org.jgrapht.*;
/**
* Generates a complete
* bipartite graph of any size. This is a graph with two partitions; two
* vertices will contain an edge if and only if they belong to different
* partitions.
*
* @author Andrew Newell
* @since Dec 21, 2008
*/
public class CompleteBipartiteGraphGenerator
implements GraphGenerator
{
private int sizeA, sizeB;
/**
* Creates a new CompleteBipartiteGraphGenerator object.
*
* @param partitionOne This is the number of vertices in the first partition
* @param partitionTwo This is the number of vertices in the second parition
*/
public CompleteBipartiteGraphGenerator(int partitionOne, int partitionTwo)
{
if ((partitionOne < 0) || (partitionTwo < 0)) {
throw new IllegalArgumentException("must be non-negative");
}
this.sizeA = partitionOne;
this.sizeB = partitionTwo;
}
/**
* Construct a complete bipartite graph
*/
@Override public void generateGraph(
Graph target,
final VertexFactory vertexFactory,
Map resultMap)
{
if ((sizeA < 1) && (sizeB < 1)) {
return;
}
//Create vertices in each of the partitions
Set a = new HashSet();
Set b = new HashSet();
for (int i = 0; i < sizeA; i++) {
V newVertex = vertexFactory.createVertex();
target.addVertex(newVertex);
a.add(newVertex);
}
for (int i = 0; i < sizeB; i++) {
V newVertex = vertexFactory.createVertex();
target.addVertex(newVertex);
b.add(newVertex);
}
//Add an edge for each pair of vertices in different partitions
for (Iterator iterA = a.iterator(); iterA.hasNext();) {
V v = iterA.next();
for (Iterator iterB = b.iterator(); iterB.hasNext();) {
target.addEdge(v, iterB.next());
}
}
}
}
// End CompleteBipartiteGraphGenerator.java