/*
* $RCSfile$
* $Author$
* $Date$
* $Revision$
*
* Copyright (C) 1997-2007 The Chemistry Development Kit (CDK) project
*
* Contact: cdk-devel@lists.sourceforge.net
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
* All we ask is that proper credit is given for our work, which includes
* - but is not limited to - adding the above copyright notice to the beginning
* of your source code files, and to any copyright notice that you may distribute
* with programs based on this work.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
package org.openscience.cdk.graph;
import java.util.Iterator;
import org.openscience.cdk.interfaces.IAtomContainer;
import org.openscience.cdk.tools.ILoggingTool;
import org.openscience.cdk.tools.LoggingToolFactory;
/**
* The permutation code here is based on a pseudo code example
* on a tutorial site created and maintained by Phillip P. Fuchs:
* <a href="http://www.geocities.com/permute_it/pseudo2.html">http://www.geocities.com/permute_it/pseudo2.html</a>.
*
*@author steinbeck
* @cdk.githash
*@cdk.created 2005-05-04
*@cdk.keyword permutation
*/
public abstract class AtomContainerPermutor
implements Iterator<IAtomContainer> {
final static boolean debug = true;
static int debugCounter = 0;
int N, i, j;
int[] bookkeeping;
Object[] objects;
private static ILoggingTool logger =
LoggingToolFactory.createLoggingTool(AtomContainerPermutor.class);
IAtomContainer atomContainer;
public void setAtomContainer(IAtomContainer ac)
{
this.atomContainer = ac;
}
public void initBookkeeping()
{
bookkeeping = new int[N + 1];
for (int f = 0; f <= N ; f++)
{
bookkeeping[f] = f;
}
i = 1;
}
public IAtomContainer next()
{
bookkeeping[i] = bookkeeping[i] - 1;
if (isOdd(i)) j = bookkeeping[i];
else j = 0;
swap(i, j);
i = 1;
while(bookkeeping[i] == 0)
{
bookkeeping[i] = i;
i++;
}
return makeResult();
}
public boolean hasNext()
{
if (i < N) return true;
return false;
}
public void remove()
{
// stupid method. not implemented.
}
void swap(int x, int y)
{
logger.debug("swapping order of " + x + " and " + y);
Object o = objects[x];
objects[x] = objects[y];
objects[y] = o;
}
void initObjectArray()
{
//
}
IAtomContainer makeResult()
{
return null;
}
/**
* Returns true if this number is odd.
*/
boolean isOdd(int x)
{
return (x & 1 ) == 1;
}
}