/*
 * @(#)ShellSortAlgorithm.java	1.0 95/06/23 Jason Harrison
 *
 * Copyright (c) 1995 University of British Columbia
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * UBC MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. UBC SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */

/**
 * An insertion sort demonstration algorithm
 * SortAlgorithm.java, Thu Oct 27 10:32:35 1994
 *
 * @author Jason Harrison@cs.ubc.ca
 * @version 	1.0, 23 Jun 1995
 *
 */
class ShellSortAlgorithm extends SortAlgorithm {
    void sort(int a[]) throws Exception {
	int h = 1;
        while (h < a.length) {
	    h = 3*h + 1;
	}
	do {
            h = h / 3;
            for (int i = h - 1; i < a.length; i++) {
                int B = a[i];
                int j = i;
                for( j = i; (j >= h) && (a[j-h] > B); j -= h) {
                    if (stopRequested) {
		        return;
                    }
                    a[j] = a[j-h];
		    pause(j);
                }
                a[j] = B;
	        pause(j);
            }
        } while (h > 0);
    }
}