/*
 * @(#)QSortAlgorithm.java	1.6f 95/01/31 James Gosling
 *
 * Copyright (c) 1994-1995 Sun Microsystems, Inc. All Rights Reserved.
 *
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 * 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.
 * 
 * SUN 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. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * THIS SOFTWARE IS NOT DESIGNED OR INTENDED FOR USE OR RESALE AS ON-LINE
 * CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING FAIL-SAFE
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 * NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
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 * PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES").  SUN
 * SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
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 */

/**
 * A quick sort demonstration algorithm
 * SortAlgorithm.java, Thu Oct 27 10:32:35 1994
 *
 * @author James Gosling
 * @version 	1.6f, 31 Jan 1995
 */
class QSortAlgorithm extends SortAlgorithm {
    void sort(int a[], int lo0, int hi0) throws Exception {
	int lo = lo0;
	int hi = hi0;
	pause(lo, hi);
	if (lo >= hi) {
	    return;
	}
	int mid = a[(lo + hi) / 2];
	while (lo < hi) {
	    while (lo<hi && a[lo] < mid) {
		lo++;
	    }
	    while (lo<hi && a[hi] > mid) {
		hi--;
	    }
	    if (lo < hi) {
		int T = a[lo];
		a[lo] = a[hi];
		a[hi] = T;
		pause();
	    }
	}
	if (hi < lo) {
	    int T = hi;
	    hi = lo;
	    lo = T;
	}
	sort(a, lo0, lo);
	sort(a, lo == lo0 ? lo+1 : lo, hi0);
    }

    void sort(int a[]) throws Exception {
	sort(a, 0, a.length-1);
	pause(-1,-1);
    }
}