org.jgrapht.generate.RingGraphGenerator 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.
*/
/* -------------------
* RingGraphGenerator.java
* -------------------
* (C) Copyright 2003-2008, by John V. Sichi and Contributors.
*
* Original Author: John V. Sichi
* Contributor(s): -
*
* $Id$
*
* Changes
* -------
* 16-Sep-2003 : Initial revision (JVS);
*
*/
package org.jgrapht.generate;
import java.util.*;
import org.jgrapht.*;
/**
* Generates a ring graph of any size. A ring graph is a graph that contains a
* single cycle that passes through all its vertices exactly once. For a
* directed graph, the generated edges are oriented consistently around the
* ring.
*
* @author John V. Sichi
* @since Sep 16, 2003
*/
public class RingGraphGenerator
implements GraphGenerator
{
private int size;
/**
* Construct a new RingGraphGenerator.
*
* @param size number of vertices to be generated
*
* @throws IllegalArgumentException if the specified size is negative.
*/
public RingGraphGenerator(int size)
{
if (size < 0) {
throw new IllegalArgumentException("must be non-negative");
}
this.size = size;
}
/**
* {@inheritDoc}
*/
public void generateGraph(
Graph target,
VertexFactory vertexFactory,
Map resultMap)
{
if (size < 1) {
return;
}
LinearGraphGenerator linearGenerator =
new LinearGraphGenerator(size);
Map privateMap = new HashMap();
linearGenerator.generateGraph(target, vertexFactory, privateMap);
V startVertex = privateMap.get(LinearGraphGenerator.START_VERTEX);
V endVertex = privateMap.get(LinearGraphGenerator.END_VERTEX);
target.addEdge(endVertex, startVertex);
}
}
// End RingGraphGenerator.java