stringquicksort.java

Myjxta的源代码 基于JXTA的P2P即时通信系统

/*
 *  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
 *  reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in
 *  the documentation and/or other materials provided with the
 *  distribution.
 *
 *  3. The end-user documentation included with the redistribution,
 *  if any, must include the following acknowledgment:
 *  "This product includes software developed by the
 *  Sun Microsystems, Inc. for Project JXTA."
 *  Alternately, this acknowledgment may appear in the software itself,
 *  if and wherever such third-party acknowledgments normally appear.
 *
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *  must not be used to endorse or promote products derived from this
 *  software without prior written permission. For written
 *  permission, please contact Project JXTA at http://www.jxta.org.
 *
 *  5. Products derived from this software may not be called "JXTA",
 *  nor may "JXTA" appear in their name, without prior written
 *  permission of Sun.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 *  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *  ====================================================================
 *
 *  This software consists of voluntary contributions made by many
 *  individuals on behalf of Project JXTA.  For more
 *  information on Project JXTA, please see
 *  <http://www.jxta.org/>.
 *
 *  This license is based on the BSD license adopted by the Apache Foundation.
 *
 *  $Id: StringQuickSort.java,v 1.2 2006/07/13 05:26:36 nano Exp $
 */
//package net.java.netbeams.store;
package net.jxta.myjxta.misc.beam;

/**
 * StringQuickSort.java
 */
public class StringQuickSort {

    private String[] a = null;
    private int[] b = null;
    /**
     * Constructor
     */
    public StringQuickSort(String [] a, boolean ignorecase) {
        this.a = a;
        b = new int[a.length];
        int i = 0;
        for (i = 0; i < a.length; i++) {
            b[i] = i;
        }

        if (ignorecase == true) {
            String tmpa[] = new String[a.length];
            for (i = 0; i < a.length; i++) {
                tmpa[i] = a[i].toUpperCase();
            }
            this.a = tmpa;
        }
    }

    /**
     * This is a generic version of C.A.R Hoare's Quick Sort
     * algorithm.  This will handle arrays that are already
     * sorted, and arrays with duplicate keys.<BR>
     *
     * @param a   an Object String array
     * @param lo0 left boundary of array partition
     * @param hi0 right boundary of array partition
     */
    protected void sort(int lo0, int hi0) {
        int lo = lo0;
        int hi = hi0;
        String mid;

        if (hi0 > lo0) {
            mid = a[b[(lo0 + hi0) / 2]];

            while (lo <= hi) {
                while ((lo < hi0) && (compare(a[b[lo]], mid) < 0)) {
                    lo++;
                }

                while ((hi > lo0) && (compare(a[b[hi]], mid) > 0)) {
                    hi--;
                }

                if (lo <= hi) {
                    swap(lo, hi);
                    lo++;
                    hi--;
                }
            }

            if (lo0 < hi) {
                sort(lo0, hi);
            }

            if (lo < hi0) {
                sort(lo, hi0);
            }
        }
    }

    private int compare(String a, String b) {
        return a.compareTo(b);
    }

    private void swap(int i, int j) {
        int T;
        T = b[i];
        b[i] = b[j];
        b[j] = T;
    }

    public int[] getSortOrder() {
        sort(0, a.length - 1);
        return b;
    }

}