/*
* Jalview - A Sequence Alignment Editor and Viewer
* Copyright (C) 2005 AM Waterhouse, J Procter, G Barton, M Clamp, S Searle
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
*/
package MCview;

import java.util.*;


public class Zsort {
    public void Zsort(Vector bonds) {
        sort(bonds, 0, bonds.size() - 1);
    }

    public void sort(Vector bonds, int p, int r) {
        int q;

        if (p < r) {
            q = partition(bonds, p, r);
            sort(bonds, p, q);
            sort(bonds, q + 1, r);
        }
    }

    private int partition(Vector bonds, int p, int r) {
        float x = ((Bond) bonds.elementAt(p)).start[2];
        int i = p - 1;
        int j = r + 1;
        Bond tmp;
        while (true) {
            do {
                j --;
            } while ((j >= 0) && (((Bond) bonds.elementAt(j)).start[2] > x));

            do {
                i ++;
            } while ((i < bonds.size()) &&
                    (((Bond) bonds.elementAt(i)).start[2] < x));

            if (i < j) {
                tmp = (Bond) bonds.elementAt(i);
                bonds.setElementAt(bonds.elementAt(j), i);
                bonds.setElementAt(tmp, j);
            } else {
                return j;
            }
        }
    }
}