/*
 * @(#)BidirBubbleSortAlgorithm.java	1.6f 95/01/31 James Gosling
 *                                  modified 96/04/24 Jim Hagen
 * Copyright (c) 1994-1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL or COMMERCIAL purposes and
 * without fee is hereby granted. 
 * Please refer to the file http://java.sun.com/copy_trademarks.html
 * for further important copyright and trademark information and to
 * http://java.sun.com/licensing.html for further important licensing
 * information for the Java (tm) Technology.
 */

/**
 * A bi-directional bubble sort demonstration algorithm
 * SortAlgorithm.java, Thu Oct 27 10:32:35 1994
 *
 * @author James Gosling
 * @version 	1.6f, 31 Jan 1995
 */
class BidirBubbleSortAlgorithm extends SortAlgorithm {
    void sort(int a[]) throws Exception {
        int j;
        int limit = a.length;
        int st = -1;
        while (st < limit) {
            boolean flipped = false;
            st++;
            limit--;
            for (j = st; j < limit; j++) {
                if (stopRequested) {
                    return;
                }
                if (a[j] > a[j + 1]) {
                    int T = a[j];
                    a[j] = a[j + 1];
                    a[j + 1] = T;
                    flipped = true;
                    pause(st, limit);
                }
            }
            if (!flipped) {
                return;
            }
            for (j = limit; --j >= st;) {
                if (stopRequested) {
                    return;
                }
                if (a[j] > a[j + 1]) {
                    int T = a[j];
                    a[j] = a[j + 1];
                    a[j + 1] = T;
                    flipped = true;
                    pause(st, limit);
                }
            }
            if (!flipped) {
                return;
            }
        }
        pause(st, limit);
    }
}